OWNER’S SERVICE MANUAL…Read this manual carefully before operating this vehicle. 2021 OWNER’S...

Read this manual carefully before operating this vehicle.

2021OWNER’S SERVICE MANUAL

YZ125X

YZ125XMLIT-11626-34-08 B1B-2819U-10

EAM20161Read this manual carefully

Operating, servicing and maintaining a passenger vehicle or off-road vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. For more information go to www.P65Warnings.ca.gov/passenger-vehicle

Read this manual carefully before operating this vehicle. This manual should stay with this vehicle if it is sold.

EAM20080

YZ125XMOWNER’S SERVICE MANUAL

©2021 by Yamaha Motor Corporation, U.S.A.First edition, March 2020

All rights reserved.Any reproduction or unauthorized use

without the written permission of Yamaha Motor Corporation, U.S.A.

is expressly prohibited.P/N. LIT-11626-34-08

EAM20180

IMPORTANTCongratulations on your purchase of a Yamaha YZ series. This model is the culmination of Yamaha’svast experience in the production of pacesetting racing machines. It represents the highest grade ofcraftsmanship and reliability that have made Yamaha a leader.This manual explains operation, inspection, basic maintenance and tuning of your machine. If you haveany questions about this manual or your machine, please contact your Yamaha dealer.TIP• Yamaha continually seeks advancements in product design and quality. Therefore, while this manual

contains the most current product information available at the time of printing, there may be minor dis-crepancies between your machine and this manual. If you have any questions concerning this man-ual, please consult your Yamaha dealer.

• This manual is intended for those who have basic knowledge and skill concerning the servicing ofYamaha motorcycles (e.g., Yamaha dealers, service engineers, etc.). Those who have little knowl-edge and skill concerning servicing are requested not to undertake inspection, adjustment, disassem-bly, or reassembly only by reference to this manual. It may lead to servicing trouble and mechanicaldamage.

WARNINGEWA20270

PLEASE READ THIS MANUAL CAREFULLY AND COMPLETELY BEFORE OPERATING THISMACHINE. DO NOT ATTEMPT TO OPERATE THIS MACHINE UNTIL YOU HAVE ATTAINED ASATISFACTORY KNOWLEDGE OF ITS CONTROLS AND OPERATING FEATURES AND UNTILYOU HAVE BEEN TRAINED IN SAFE AND PROPER RIDING TECHNIQUES. REGULAR INSPEC-TIONS AND CAREFUL MAINTENANCE, ALONG WITH GOOD RIDING SKILLS, WILL ENSURETHAT YOU SAFETY ENJOY THE CAPABILITIES AND THE RELIABILITY OF THIS MACHINE.

EAM30001

IMPORTANT MANUAL INFORMATIONParticularly important information is distinguished in this manual by the following notations.

This is the safety alert symbol. It is used to alert you to potential per-sonal injury hazards. Obey all safety messages that follow this symbol to avoid possible injury or death.

A WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury.

A NOTICE indicates special precautions that must be taken to avoid damage to the vehicle or other property.

A TIP provides key information to make procedures easier or clearer.

WARNING

NOTICE

TIP

EAM20162

YAMAHA MOTOR CORPORATION, U.S.A. YZ MOTORCYCLE LIMITED WARRANTY

EAM20082

HOW TO USE THIS MANUALIn this manual, descriptions of installation, removal, disassembly, assembly, check, and adjustmentprocedures are laid out with the individual steps in sequential order.• The manual is divided into chapters and each chapter is divided into sections. The current section title

“1” is shown at the top of each page.• Sub-section titles “2” appear in smaller print than the section title.• To help identify parts and clarify procedure steps, there are exploded diagrams “3” at the start of each

removal and disassembly section.• Numbers “4” are given in the order of the jobs in the exploded diagram. A number indicates a removal

or a disassembly step.• Symbols “5” indicate parts to be lubricated or replaced.

Refer to “SYMBOLS”.• A job instruction chart “6” accompanies the exploded diagram, providing the order of jobs, the names

of parts, the notes in jobs, etc. This step explains removal and disassembly procedure only. For in-stallation and assembly procedure, reverse the steps.

• Jobs “7” requiring more information (such as special tools and technical data) are described sequen-tially.

1

7

3

5

4

6

2

G088877

EAM20083

SYMBOLSThe following symbols are used in this manual for easier understanding.TIPThe following symbols are not relevant to every vehicle.

SYMBOL DEFINITION SYMBOL DEFINITION

Serviceable with engine mounted Gear oil

Filling fluid Molybdenum disulfide oil

Lubricant Brake fluid

Special tool Wheel bearing grease

Tightening torque Lithium-soap-based grease

Wear limit, clearance Molybdenum disulfide grease

Engine speed Silicone grease

Electrical data Apply locking agent (LOCTITE®).

Engine oil Replace the part with a new one.

G

M

BF

B

T R..

LS

M

S

LT

ENew

GENERAL INFORMATION 1

SPECIFICATIONS 2PERIODIC CHECKS AND ADJUSTMENTS 3

CHASSIS 4

ENGINE 5

COOLING SYSTEM 6

FUEL SYSTEM 7

ELECTRICAL SYSTEM 8

TROUBLESHOOTING 9

TUNING 10

EAM10003

TABLE OF CONTENTS

1

2

3

4

5

6

7

8

9

10

GENERAL INFORMATION

SAFETY INFORMATION ..................................................................................1-1FOR SAFETY, BE SURE TO OBEY THE FOLLOWING:...........................1-1

LOCATION OF IMPORTANT LABELS.............................................................1-4

DESCRIPTION..................................................................................................1-5

IDENTIFICATION ..............................................................................................1-6VEHICLE IDENTIFICATION NUMBER ......................................................1-6ENGINE SERIAL NUMBER........................................................................1-6

INCLUDED PARTS ...........................................................................................1-7NIPPLE WRENCH......................................................................................1-7VALVE JOINT.............................................................................................1-7COLLAR (tool for YPVS) ............................................................................1-7

IMPORTANT INFORMATION ...........................................................................1-8PREPARATION FOR REMOVAL AND DISASSEMBLY............................1-8REPLACEMENT PARTS............................................................................1-8GASKETS, OIL SEALS AND O-RINGS .....................................................1-8LOCK WASHERS/PLATES AND COTTER PINS ......................................1-9BEARINGS AND OIL SEALS .....................................................................1-9CIRCLIPS ...................................................................................................1-9

BASIC SERVICE INFORMATION...................................................................1-10ELECTRICAL SYSTEM............................................................................1-10

SPECIAL TOOLS............................................................................................1-12

INSTRUMENT AND CONTROL FUNCTIONS ...............................................1-16ENGINE STOP SWITCH ..........................................................................1-16SHIFT PEDAL...........................................................................................1-16KICKSTARTER LEVER............................................................................1-16FRONT BRAKE LEVER ...........................................................................1-16REAR BRAKE PEDAL..............................................................................1-16FUEL COCK .............................................................................................1-16STARTER KNOB (CHOKE)......................................................................1-17SIDESTAND .............................................................................................1-17

STARTING AND BREAK-IN ...........................................................................1-18FUEL AND ENGINE MIXING OIL.............................................................1-18STARTING A COLD ENGINE ..................................................................1-18STARTING A WARM ENGINE .................................................................1-18BREAK-IN PROCEDURES ......................................................................1-18

MAINTENANCE AFTER BREAK-IN ..............................................................1-20MAJOR MAINTENANCE ..........................................................................1-20AIR FILTER MAINTENANCE ...................................................................1-20

TORQUE-CHECK POINTS.............................................................................1-21

MOTORCYCLE CARE AND STORAGE.........................................................1-23CARE........................................................................................................1-23STORAGE ................................................................................................1-24

SAFETY INFORMATION

1-1

EAM20168

SAFETY INFORMATIONBe sure to read this manual carefully and com-pletely in order to operate the machine safelyand correctly prior to riding the Yamaha ma-chine, and take care to maintain it properly andoperate it safely.

EAM30401

FOR SAFETY, BE SURE TO OBEY THE FOLLOWING:Be a Responsible OwnerAs the vehicle’s owner, you are responsible forthe safe and proper operation of your motorcy-cle.Motorcycles are single-track vehicles.Their safe use and operation are dependentupon the use of proper riding techniques as wellas the expertise of the operator. Every operatorshould know the following requirements beforeriding this motorcycle.He or she should:1. Obtain thorough instructions from a compe-

tent source on all aspects of motorcycle oper-ation.

2. Observe the warnings and maintenance re-quirements in this manual.

3. Obtain qualified training in safe and properriding techniques.

4. Obtain professional technical service as indi-cated in this manual and/or when made nec-essary by mechanical conditions.

5. Never operate a motorcycle without propertraining or instruction. Take a training course.Beginners should receive training from a cer-tified instructor. Contact an authorized motor-cycle dealer to find out about the trainingcourses nearest you.

Safe RidingPerform the pre-operation checks each time youuse the vehicle to make sure it is in safe operat-ing condition. Failure to inspect or maintain thevehicle properly increases the possibility of anaccident or equipment damage. Refer to “PRE-OPERATION INSPECTION AND MAINTE-NANCE” on page 3-4 for a list of pre-operationchecks.1. This motorcycle is designed for off-road use

only, therefore, it is illegal to operate it onpublic streets, roads, or highways, even a dirtor gravel one. Off-road use on public landsmay be illegal. Please check local regulationsbefore riding.

2. This motorcycle is designed to carry the oper-

ator only. No passengers.3. The failure of motorists to detect and recog-

nize motorcycles in traffic is the predominat-ing cause of automobile/motorcycleaccidents. Many accidents have beencaused by an automobile driver who did notsee the motorcycle. Making yourself conspic-uous appears to be very effective in reducingthe chance of this type of accident.Therefore:

• Wear a brightly colored jacket.• Use extra caution when you are approaching

and passing through intersections, since in-tersections are the most likely places for mo-torcycle accidents to occur.

• Ride where other motorists can see you.Avoid riding in another motorist’s blind spot.

• Never maintain a motorcycle without properknowledge. Contact an authorized motorcy-cle dealer to inform you on basic motorcyclemaintenance. Certain maintenance can onlybe carried out by certified staff.

4. Many accidents involve inexperienced opera-tors.

• Make sure that you are qualified and that youonly lend your motorcycle to other qualifiedoperators.

• Know your skills and limits. Staying withinyour limits may help you to avoid an accident.

• We recommend that you practice riding yourmotorcycle until you have become thoroughlyfamiliar with the motorcycle and all of its con-trols.

5. Many accidents have been caused by error ofthe motorcycle operator. A typical error madeby the operator is veering wide on a turn dueto excessive speed or under cornering (insuf-ficient lean angle for the speed). Never travelfaster than warranted by conditions.

6. Ride cautiously in unfamiliar areas. You mayencounter hidden obstacles that could causean accident.

7. The posture of the operator is important forproper control. The operator should keepboth hands on the handlebar and both feet onthe operator footrests during operation tomaintain control of the motorcycle.

8. Never ride under the influence of alcohol orother drugs.

9. Be sure the transmission is in neutral beforestarting the engine.

Protective ApparelThe majority of fatalities from motorcycle acci-

SAFETY INFORMATION

1-2

dents are the result of head injuries. The use ofa safety helmet is the single most critical factorin the prevention or reduction of head injuries.1. Always wear an approved helmet.2. Wear a face shield or goggles. Wind in your

unprotected eyes could contribute to an im-pairment of vision that could delay seeing ahazard.

3. The use of a jacket, heavy boots, trousers,gloves, etc., is effective in preventing or re-ducing abrasions or lacerations.

4. Never wear loose-fitting clothes, otherwisethey could catch on the control levers, foot-rests, or wheels and cause injury or an acci-dent.

5. Always wear protective clothing that coversyour legs, ankles, and feet. The engine or ex-haust system become very hot during or afteroperation and can cause burns.

Avoid Carbon Monoxide PoisoningAll engine exhaust contains carbon monoxide, adeadly gas. Breathing carbon monoxide cancause headaches, dizziness, drowsiness, nau-sea, confusion, and eventually death.Carbon Monoxide is a colorless, odorless, taste-less gas which may be present even if you donot see or smell any engine exhaust. Deadly lev-els of carbon monoxide can collect rapidly andyou can quickly be overcome and unable to saveyourself. Also, deadly levels of carbon monoxidecan linger for hours or days in enclosed or poorlyventilated areas. If you experience any symp-toms of carbon monoxide poisoning, leave thearea immediately, get fresh air, and SEEK MED-ICAL TREATMENT.1. Do not run engine indoors. Even if you try to

ventilate engine exhaust with fans or openwindows and doors, carbon monoxide canrapidly reach dangerous levels.

2. Do not run engine in poorly ventilated or par-tially enclosed areas such as barns, garages,or carports.

3. Do not run engine outdoors where engine ex-haust can be drawn into a building throughopenings such as windows and doors.

Genuine Yamaha AccessoriesChoosing accessories for your vehicle is an im-portant decision. Genuine Yamaha accessories,which are available only from a Yamaha dealer,have been designed, tested, and approved byYamaha for use on your vehicle.Many companies with no connection to Yamahamanufacture parts and accessories or offer oth-

er modifications for Yamaha vehicles. Yamahais not in a position to test the products that theseaftermarket companies produce. Therefore,Yamaha can neither endorse nor recommendthe use of accessories not sold by Yamaha ormodifications not specifically recommended byYamaha, even if sold and installed by a Yamahadealer.Aftermarket Parts, Accessories, and Modifi-cationsWhile you may find aftermarket products similarin design and quality to genuine Yamaha acces-sories, recognize that some aftermarket acces-sories or modifications are not suitable becauseof potential safety hazards to you or others. In-stalling aftermarket products or having othermodifications performed to your vehicle thatchange any of the vehicle’s design or operationcharacteristics can put you and others at greaterrisk of serious injury or death. You are responsi-ble for injuries related to changes in the vehicle.Keep the following guidelines in mind, as well asthose provided under “Loading” when mountingaccessories.1. Never install accessories that would impair

the performance of your motorcycle. Careful-ly inspect the accessory before using it tomake sure that it does not in any way reduceground clearance or cornering clearance, lim-it suspension travel, steering travel or controloperation.

• Accessories fitted to the handlebar or thefront fork area can create instability due to im-proper weight distribution. If accessories areadded to the handlebar or front fork area,they must be as lightweight as possible andshould be kept to a minimum.

• Bulky or large accessories may seriously af-fect the stability of the motorcycle. Wind mayattempt to lift the motorcycle, or the motorcy-cle may become unstable in cross winds.

• Certain accessories can displace the opera-tor from his or her normal riding position. Thisimproper position limits the freedom of move-ment of the operator and may limit controlability, therefore, such accessories are notrecommended.

2. Use caution when adding electrical accesso-ries. If electrical accessories exceed the ca-pacity of the motorcycle’s electrical system,an electric failure could result, which couldcause a dangerous loss of lights or enginepower.

SAFETY INFORMATION

1-3

Aftermarket Tires and RimsThe tires and rims that came with your motorcy-cle were designed to match the performance ca-pabilities and to provide the best combination ofhandling, braking, and comfort. Other tires, rims,sizes, and combinations may not be appropriate.Refer to “CHECKING THE TIRES” on page 3-23for tire specifications and more information onreplacing your tires.Transporting the MotorcycleBe sure to observe following instructions beforetransporting the motorcycle in another vehicle.1. Remove all loose items from the motorcycle.2. Check that the fuel cock (if equipped) is in the

“OFF” position and that there are no fuelleaks.

3. Point the front wheel straight ahead on thetrailer or in the truck bed, and choke it in a railto prevent movement.

4. Shift the transmission in gear (for models witha manual transmission).

5. Secure the motorcycle with tie-downs or suit-able straps that are attached to solid parts ofthe motorcycle, such as the frame or upperfront fork triple clamp (and not, for example,to rubber-mounted handlebars or turn sig-nals, or parts that could break). Choose thelocation for the straps carefully so the strapswill not rub against painted surfaces duringtransport.

6. The suspension should be compressedsomewhat by the tie-downs, if possible, sothat the motorcycle will not bounce exces-sively during transport.

LOCATION OF IMPORTANT LABELS

1-4

EAM20085

LOCATION OF IMPORTANT LABELSPlease read the following important labels carefully before operating this vehicle.

3, 42

5

1

DESCRIPTION

1-5

EAM20086

DESCRIPTION

TIPDesigns and specifications of the vehicle are subject to change without notice. Therefore, please notethat the descriptions in this manual may be different from those for the vehicle you have purchased.

12

7 8

1 3

9

11 10 19

13 14 15

18 1617

2 4

6 5

1. Clutch lever2. Engine stop switch3. Front brake lever4. Throttle grip5. Radiator cap6. Fuel tank cap7. Kickstarter lever8. Fuel tank9. Radiator10.Coolant drain bolt

11.Check bolt (Transmission oil level)12.Rear brake pedal13.Valve joint14.Fuel cock15.Air filter16.Drive chain17.Shift pedal18.Starter knob19.Front fork

IDENTIFICATION

1-6

EAM20087

IDENTIFICATIONThere are two significant reasons for knowingthe serial number of your vehicle:1. When ordering parts, you can give the num-

ber to your Yamaha dealer for positive identi-fication of the model you own.

2. If your vehicle is stolen, the authorities willneed the number to search for and identifyyour vehicle.

EAM30002

VEHICLE IDENTIFICATION NUMBERThe vehicle identification number “1” is stampedinto the right side of the frame.

EAM30003

ENGINE SERIAL NUMBERThe engine serial number “1” is stamped into theelevated part of the right-side of the engine.

INCLUDED PARTS

1-7

EAM20088

INCLUDED PARTSEAM30005

NIPPLE WRENCHThe nipple wrench “1” is used to tighten thespoke.

EAM30534

VALVE JOINTThis valve joint “1” prevents fuel from flowing outand is installed to the fuel tank breather hose.

NOTICEECA27110

In this installation, make sure the arrow fac-es the fuel tank and also downward.

EAM30615

COLLAR (tool for YPVS)This collar “1” is used to remove and install thepush rod of the engine.

NOTICEECA27100

Be sure to use the collar. If the collar is notused, the power valve constituent parts willresult in damage.

IMPORTANT INFORMATION

1-8

EAM20089

IMPORTANT INFORMATIONEAM30009

PREPARATION FOR REMOVAL AND DISASSEMBLY1. Before the jobs, completely remove mud,

dust, and the like in order to prevent the entryof them into the inside during the jobs.Refer to “CARE” on page 1-23.

2. Use proper special tools and equipment. Re-fer to “SPECIAL TOOLS” on page 1-12.

3. During disassembly, check and measure therequired parts, and make a record of them sothat you may refer to the record when install-ing them. Moreover, arrange gears, cylin-ders, pistons, and other parts for each sectionso as not to confuse or lose them.

4. During disassembly, clean each of the parts,and store them in trays for each section.

5. Flammable. Keep servicing areas away fromany source of fire.

6. During servicing, take special care not to re-

ceive an injury or a burn on the engine, theexhaust pipe, the silencer, or the like.

7. If coolant is left adhered to the chassis, paintand plating will be damaged. Therefore, rinseit out with water in good time.

WARNINGEWA18970

Coolant is potentially harmful and should behandled with special care.• If it enters your eyes, wash it away with wa-

ter enough and then get medical attention• If it splashes on your skin or clothes, quick-

ly wash it away with water and then withsoapy water.

• If it is swallowed, immediately induce vom-iting and get medical attention.

EAM30010

REPLACEMENT PARTSMake sure that the parts and grease or oil to beused for repair of the vehicle, including periodicreplacement parts, are new YAMAHA genuineparts and recommended parts.Do not use any used parts, because these maynot be genuine though they have similar appear-ances or because the quality may be changedby aging.

EAM30011

GASKETS, OIL SEALS AND O-RINGS1. When overhauling the engine, replace all

gaskets and O-rings. All gasket surfaces, oilseal lips, and O-rings must be cleaned so thatthere may be no dust on them.

2. During assembly, always apply proper oil tobearings and proper grease to oil seal lips be-fore installation.

IMPORTANT INFORMATION

1-9

EAM30012

LOCK WASHERS/PLATES AND COTTER PINSAfter removal, replace lock washers/plates “1”and cotter pins with new ones. After the bolt ornut has been tightened to specification, firmlybend the lock tabs along a flat of the bolt or nut.

EAM30013

BEARINGS AND OIL SEALSInstall bearings “1” and oil seals “2” with theirmanufacturer’s marks or size symbols facingoutward. During installation of an oil seal, makesure that its main lip faces the oil chamber (thetarget to be sealed). Before installation, alwaysapply a light coat of grease to the oil seal lip.

NOTICEECA13300

Do not spin the bearing with compressed airbecause this will damage the bearing surfac-es.

EAM30014

CIRCLIPSWhen assembling parts, always use new cir-clips. During installation of a circlip, make surethat the edge “2” of the circlip “1” is positionedopposite to the force “3” that the circlip receives.Install the circlip with its end aligned with thecenter of the spline, without opening the circlipmore than necessary.

1. Oil2. Lip3. Spring4. Grease

BASIC SERVICE INFORMATION

1-10

EAM20120

BASIC SERVICE INFORMATIONEAM30181

ELECTRICAL SYSTEMChecking the electrical system

NOTICEECA14371

Never insert the tester probes into the cou-pler terminal slots. Always insert the probesfrom the opposite end “a” of the coupler, tak-ing care not to loosen or damage the leads.

NOTICEECA16640

For waterproof couplers, never insert thetester probes directly into the coupler. Whenperforming any checks using a waterproofcoupler, use the specified test harness or asuitable commercially available test har-ness.

Checking the connectionsCheck the leads, couplers, and connectors forstains, rust, moisture, etc.1. Disconnect:

• Lead• Coupler• Connector

NOTICEECA16780

• When disconnecting a coupler, release thecoupler lock, hold both sections of the cou-pler securely, and then disconnect the cou-pler.

• There are many types of coupler locks;therefore, be sure to check the type of cou-pler lock before disconnecting the coupler.

NOTICEECA16790

When disconnecting a connector, do not pullthe leads. Hold both sections of the connec-tor securely, and then disconnect the con-nector.

2. Check:• Lead• Coupler• Connector

Moisture Dry with compressed air.Rust/stains Connect and disconnect sev-eral times.

3. Check:• All connections

Loose connection Connect properly.

a

BASIC SERVICE INFORMATION

1-11

TIP• If the pin “1” on the terminal is flattened, bend

it up.• After disassembling or assembling a coupler,

pull on the leads to make sure that they are in-stalled securely.

4. Connect:• Lead• Coupler• Connector

TIP• When connecting a coupler or connector,

make sure that both terminals are connectedsecurely.

• Make sure all connections are tight.

5. Check:• No continuity

TIP• If there is no continuity, clean the terminals.• When checking the wire harness, perform

steps (1) to (4).• As a quick remedy, use a contact revitalizer

available at most part stores.

1

Digital circuit tester (CD732)90890-03243

Model 88 Multimeter with tachom-eter

YU-A1927

SPECIAL TOOLS

1-12

EAM20121

SPECIAL TOOLSThe following special tools are required for accurate and complete adjustment and assembly. Using thecorrect special tool will help prevent damage caused by the use of improper tools or improvised tech-niques. The shape and tool number used for the special tool differ by country, so two types are provid-ed. Refer to the list provided to avoid errors when placing an order.TIP• For U.S.A. and Canada, use tool number starting with “YM-”, “YU-”, or “ACC-”.• For others, use tool number starting with “90890-”.

Tool name/Tool No. Illustration Referencepages

Digital circuit tester (CD732)90890-03243Model 88 Multimeter with tachometerYU-A1927

1-11, 8-5, 8-6, 8-6, 8-7, 8-7, 8-7, 8-8

Steering nut wrench90890-01403Exhaust flange nut wrenchYU-A9472

3-18, 4-51

Spoke nipple wrench (6–7)90890-01521Spoke nipple wrench (6–7)YM-01521

3-24

Dial gauge & stand set90890-01252Dial gauge setYU-03097-B

3-26

Cap bolt ring wrench90890-01501Cap bolt ring wrenchYM-01501

4-40, 4-40, 4-41, 4-43, 4-47, 4-48

Cap bolt wrench90890-01500Cap bolt wrenchYM-01500

4-41, 4-43

Fork seal driver90890-01502Fork seal driver (48)YM-A0948

4-45, 4-45

SPECIAL TOOLS

1-13

Piston pin puller set90890-01304Piston pin pullerYU-01304

5-7

Rotor holding tool90890-01235Universal magneto and rotor holderYU-01235

5-16, 5-17

Flywheel puller90890-01189Flywheel pullerYM-01189

5-16

Universal clutch holder90890-04086Universal clutch holderYM-91042

5-28, 5-30

Thickness gauge90890-03268Feeler gauge setYU-26900-9

5-28


YU-01304

SPECIAL TOOLS

1-14

Crankcase separating tool90890-01135Crankcase separatorYU-01135-B

5-37, 5-41

Yamaha bond No. 121590890-85505(Three bond No.1215®)

5-38

Crankshaft installer pot90890-01274Installing potYU-90058

5-38, 5-41

Crankshaft installer bolt90890-01275BoltYU-90060

5-38, 5-41

Adapter (M8)90890-01499Adapter (M8)YM-01499

5-38

Adapter (M12)90890-01278Adapter #3YU-90063

5-41


YU-90058/YU-90059

SPECIAL TOOLS

1-15

Radiator cap tester90890-01325Mityvac cooling system tester kitYU-24460-A

6-3, 6-3

Radiator cap tester adapter90890-01352Pressure tester adapterYU-33984

6-3, 6-3

Fuel level gauge adapter90890-01470Fuel level gauge adapterYM-01470

7-10

Fuel level gauge90890-01312Fuel level gaugeYM-01312-A

7-10

Ignition checker90890-06754Oppama pet–4000 spark checkerYM-34487

8-6


YU-24460-A

YU-33984

INSTRUMENT AND CONTROL FUNCTIONS

1-16

EAM20181

INSTRUMENT AND CONTROL FUNCTIONSEAM30182

ENGINE STOP SWITCHThe engine stop switch “1” is located on the lefthandlebar. Continue pushing the engine stopswitch till the engine comes to a stop.

EAM30185

SHIFT PEDALThe shift pedal “1” has adopted a method of 1down & 5 ups (press-down & kick-ups).Press it down for N (neutral) to 1st, and kick it upfor 2nd to 6th.

EAM30186

KICKSTARTER LEVERRotate the kickstarter lever “1” away from the en-gine. Push the starter down lightly with your footuntil the gears engage, then kick smoothly andforcefully to start the engine. This model has aprimary kickstarter lever so the engine can bestarted in any gear if the clutch is disengaged. Innormal practices, however, shift to neutral be-fore starting.

EAM30188

FRONT BRAKE LEVERThe front brake lever “1” is located on the righthandlebar. Pull it toward the handlebar to acti-vate the front brake.

EAM30189

REAR BRAKE PEDALThe rear brake pedal “1” is in the right of thechassis. Press down on the brake pedal to acti-vate the rear brake.

EAM30611

FUEL COCKThe fuel cock supplies fuel from the tank to car-buretor and also filters the fuel. The fuel cockhas the three positions:OFF:With the lever in this position, fuel will not flow.Always return the lever to this position when theengine is not running.ON:With the lever in this position, fuel flows to thecarburetor. Normal riding is done with the lever

1

INSTRUMENT AND CONTROL FUNCTIONS

1-17

in this position.RES:With the lever in this position fuel flows to thecarburetor from the reserve section of the fueltank after the main supply of the fuel has beendepleted. Normal riding is possible with the leveris in this position, but it is recommended to addfuel as soon as possible.

EAM30444

STARTER KNOB (CHOKE)When cold, the engine requires a richer air-fuelmixture for starting. A separate starter circuit,which is controlled by the starter knob “1”, sup-plies this mixture. Pull the starter knob out toopen the circuit for starting. When the enginehas warmed up, push it in to close the circuit.

EAM30190

SIDESTANDThis sidestand “1” is used to support only themachine when standing or transporting it.

WARNINGEWA18980

• Never apply additional force to the sides-tand.

• Hold up the sidestand before starting out.

STARTING AND BREAK-IN

1-18

EAM20123

STARTING AND BREAK-INEAM30538

FUEL AND ENGINE MIXING OILMix oil with the gas at the ratio specified below.Always use fresh, name-brand gasoline, andmix the oil and gas the day of the race. Do notuse premix that is more than a few hours old.

TIPIf knocking or pinging occurs, use a differentbrand of gasoline or higher octane grade.

NOTICEECA22260

Never mix two types of oil in the same batch;clotting of the oil could result. If you wish tochange oil types, be sure to drain the fueltank and the carburetor float bowl of old pre-mix prior to filling with the new type.

EAM30196

STARTING A COLD ENGINE1. Shift the transmission into neutral.2. Turn the fuel cock to “ON” and full open the

starter knob (CHOKE).3. With the throttle completely closed start the

engine by kicking the kickstarter forcefully

with firm stroke.4. Run the engine at idle or slightly higher until it

warms up: this usually takes about one or twominutes.

5. The engine is warmed up when it respondsnormally to the throttle with the starter knob(CHOKE) turned off.

WARNINGEWA19030

Since exhaust gas contains harmful ingredi-ents, do not start or warm it up at an illventi-lated place or a closed narrow place.

6. To stop the engine, push the engine stopswitch.

TIPContinue pushing the engine stop switch till theengine comes to a full stop.

EAM30197

STARTING A WARM ENGINEDo not operate the starter knob (CHOKE). Openthe throttle slightly and start the engine by kick-ing the kickstarter forcefully with firm stroke.

EAM30198

BREAK-IN PROCEDURESA break-in is important so that rotating portion,sliding surfaces, and mounted areas may fit oneanother, and that the rider may become accus-tomed to the machine.

NOTICEECA25811

Before running, do maintenance on the airfilter element.

1. Before starting the engine, fill the fuel tankwith a break-in oil-fuel mixture as follows.

2. Start and warm up the engine.3. After warming up the engine, drive it for about

20 minutes at a throttle opening of 1/2 or less.4. Make a pit stop, and check mounted areas for

looseness, oil leaks, or other problems.5. Then, drive it for about 40 minutes at a throt-

tle opening of 3/4 or less.6. Make a pit stop again, and thoroughly check

mounted areas for looseness, oil leaks, orother problems. Thorough checks and ad-justments are required in particular for stretchof cables, free play of the brake, stretch of the

Recommended fuelPremium unleaded gasoline (E10 acceptable)

Fuel tank capacity8.0 L (2.1 US gal, 1.8 Imp.gal)

Fuel reserve amount2.0 L (0.53 US gal, 0.44 Imp.gal)

Engine oilLubrication system

Premix lubricationEngine oil

YAMALUBE 2RPremix ratio

30

Engine oilYAMALUBE 2R

Premix ratio15

STARTING AND BREAK-IN

1-19

drive chain, looseness of the spoke, and soon.

NOTICEECA25821

After a break-in or after each race, alwayscheck the points shown in “TORQUE-CHECK POINTS” for tightening torques andretighten them.Also when the following parts are replaced, abreak-in is required.• Cylinder and Crankshaft: A break-in is re-

quired for about an hour.• Piston, Piston ring, Valve, Camshaft, and

Gear: A break-in is required for about 30minutes at a throttle opening of 1/2 or less.

Observe the condition of the engine carefullyduring a break-in.For checkpoints for a break-in, see “MAIN-TENANCE AFTER BREAK-IN”. If any prob-lem is found, immediately stop the engineand make a checkup.

MAINTENANCE AFTER BREAK-IN

1-20

EAM20124

MAINTENANCE AFTER BREAK-INAfter a break-in, perform careful maintenance toget ready for the next practice or race.Refer to “PRE-OPERATION INSPECTION ANDMAINTENANCE” on page 3-4.

EAM30199

MAJOR MAINTENANCE1. For the engine

• Leaks around the engineCheck for pressure leaks from the cylinderhead or the cylinder, oil leaks from the crank-case or the case cover, leaks from the cool-ant system, and other leaks.

• Check that the cylinder, the piston, and thepiston ring fit one another, and that contactbetween the cylinder and the piston are cor-rect.

• Transmission oil changeDrain the oil, and check for dirt and foreignmaterials such as metal chips. (If any foreignmaterial is mixed, disassemble and check thetransmission.) Pour the specified amount of the recom-mended oil.

• CarburetorDisassemble the carburetor and clean thesmall holes, blowing them with compressedair.

• CDI magnetoCheck for looseness in mounted areas of therotor and the stator. Check that the connector is not being discon-nected.

• SilencerCheck the main body and stay for cracks. Check for leaks.

• Mounting bolts and nutsCheck for looseness in mounted areas ofparts, as well as engine mounting bolts andengine brackets.

2. For the chassis• Check welds and mounted areas of the

frame, the swingarm, the link, the bracket,and so on, for looseness and cracks.

• Wheel(s)Check the wheel for runout. Check the spokefor looseness.

• Brake(s)Check the brake disc mounting bolt for loose-ness. Check that the reservoir contains the speci-fied amount of brake fluid. Check for leaks.

• CableGrease and adjust cables.

• Drive chainLubricate the drive chain and adjust its ten-sion.

• Fuel tankClean the inside of the fuel tank and the fuelcock. Check for leaks.

• SuspensionCheck for oil leaks in the front fork or the rearshock absorber. Check that the mountedconditions are good.

• SprocketCheck for looseness in the sprocket mountedon the rear wheel.

• Mounting bolts and nutsCheck mounted areas for looseness.

NOTICEECA25831

After a break-in or before each race, alwayscheck the points shown in “TORQUE-CHECK POINTS” for tightening torques andretighten them.

• Greasing and oilingAlways grease or oil the specified points.

EAM30195

AIR FILTER MAINTENANCEApply the Yamaha foam air filter oil or other qual-ity foam air filter oil to the element. (Excess oil inthe element may adversely affect engine start-ing.)Refer to “CLEANING THE AIR FILTER ELE-MENT” on page 3-8.

TORQUE-CHECK POINTS

1-21

EAM20125

TORQUE-CHECK POINTSFrame construction Frame to rear frame

Combined seat and fuel tank Fuel tank to frame

Engine mounting Frame to engine

Engine bracket to engine

Engine bracket to frame

Seat Seat to frame

Steering Steering stem to handlebar Steering stem to frame

Steering stem to upper bracket

Upper bracket to handlebar

Suspension Front Steering stem to front fork Front fork to upper bracket

Front fork to lower bracket

Rear Link Assembly of links

Link to frame

Link to rear shock absorber

Link to swingarm

Mounting of rear shock absorber Rear shock absorber and frame

Mounting of swingarm Tightening of pivot shaft

Wheel(s) Mounting of wheel Front Tightening of wheel axle

Tightening of axle holder

Tightening of spoke nipple

Rear Tightening of wheel axle

Wheel to rear wheel sprocket

Tightening of spoke nipple

Brake(s) Front Brake caliper to front fork

Brake disc to wheel

Tightening of union bolt

Brake master cylinder to handlebar

Tightening of bleed screw

Tightening of brake hose holder

Rear Brake pedal to frame

Brake disc to wheel

Tightening of union bolt

Brake master cylinder to frame

Tightening of bleed screw

Tightening of brake hose holder

Fuel system Fuel pump to fuel tank

Shift pedal Shift pedal to shift shaft

TORQUE-CHECK POINTS

1-22

TIPConcerning the tightening torque, refer to “TIGHTENING TORQUES” on page 2-9.

Plastic cover Tightening of front fender

Tightening of fork leg protector

Tightening of air scoop

Left cover to rear frame

Tightening of side cover

Tightening of rear fender

Tightening of mud flap

Tightening of rear brake disc cover

Tightening of rear brake caliper cover

MOTORCYCLE CARE AND STORAGE

1-23

EAM20126

MOTORCYCLE CARE AND STOR-AGEEAM30200

CAREWhile the open design of a motorcycle revealsthe attractiveness of the technology, it alsomakes it more vulnerable. Rust and corrosioncan develop even if high-quality components areused. A rusty exhaust pipe may go unnoticed ona car, however, it detracts from the overall ap-pearance of a motorcycle. Frequent and propercare does not only comply with the terms of thewarranty, but it will also keep your motorcyclelooking good, extend its life and optimize its per-formance.Before cleaningTIPBe sure to confirm that the vehicle is completelycooled.

1. Block or cover the following parts with suit-able measures.

• Side cover air intake port “1”• Water pump housing hole at the bottom “2”• Crankcase cover hole at the bottom (left side)

“3”• Silencer exhaust port “4”• End of each hose

2. Make sure that all caps and covers as well asall electrical couplers and connectors, includ-ing the spark plug cap, are tightly installed.

3. Remove extremely stubborn dirt, like oil burntonto the crankcase, with a degreasing agentand a brush, but never apply such productsonto seals, gaskets, sprockets, the drivechain and wheel axles. Always rinse the dirtand degreaser off with water.

Cleaning

NOTICEECA26730

• Avoid using strong acidic wheel cleaners,especially on spoked wheels. If such prod-

ucts are used on hard-to-remove dirt, donot leave the cleaner on the affected areaany longer than instructed. Also, thorough-ly rinse the area off with water, immediatelydry it, and then apply a corrosion protec-tion spray.

• Improper cleaning can damage plasticparts (such as cowlings, panels, wind-shields, headlight lenses, meter lenses,etc.) and the mufflers. Use only a soft, cleancloth or sponge with water to clean plastic.However, if the plastic parts cannot be thor-oughly cleaned with water, diluted mild de-tergent with water may be used. Be sure torinse off any detergent residue using plentyof water, as it is harmful to plastic parts.

• Do not use any harsh chemical products onplastic parts. Be sure to avoid using clothsor sponges which have been in contactwith strong or abrasive cleaning products,solvent or thinner, fuel (gasoline), rust re-movers or inhibitors, brake fluid, antifreezeor electrolyte.

• For motorcycles equipped with a wind-shield: Do not use strong cleaners or hardsponges as they will cause dulling orscratching. Some cleaning compounds forplastic may leave scratches on the wind-shield. Test the product on a small hiddenpart of the windshield to make sure that itdoes not leave any marks. If the windshieldis scratched, use a quality plastic polishingcompound after washing.

• When cleaning using either a high-pres-sure cleaning machine or a water hose, donot direct the water jet toward the followingareas:(Otherwise, it could cause eitherdamage due to the water pressure or mal-function due to water entry.)Wheels or swing arm bearingsFork seals or brake sealsElectrical parts, such as couplers, switch-es, battery, etc.Muffler or hosesAir cleaner intake port

• Do not clean using a water jet with the seator cover removed.

1

2

4

3


1-24

After normal useRemove dirt with warm water, a mild detergent,and a soft, clean sponge, and then rinse thor-oughly with clean water. Use a toothbrush orbottlebrush for hard-to-reach areas. Stubborndirt and insects will come off more easily if thearea is covered with a wet cloth for a few min-utes before cleaning.After riding in the rain, near the sea or on salt-sprayed roadsSince sea salt or salt sprayed on roads duringwinter are extremely corrosive in combinationwith water, carry out the following steps aftereach ride in the rain, near the sea or on salt-sprayed roads.TIPSalt sprayed on roads in the winter may remainwell into spring.

1. Clean the motorcycle with cold water and amild detergent, after the engine has cooleddown. NOTICE: Do not use warm water since itincreases the corrosive action of the salt.

2. Apply a corrosion protection spray on all met-al, including chrome- and nickel-plated, sur-faces to prevent corrosion.

After cleaning1. Dry the motorcycle with a chamois or an ab-

sorbing cloth.2. Immediately dry the drive chain and lubricate

it to prevent it from rusting.3. Use a chrome polish to shine chrome, alumi-

num and stainless- steel parts, including theexhaust system. (Even the thermally induceddiscoloring of stainless- steel exhaust sys-tems can be removed through polishing.)

4. To prevent corrosion, it is recommended toapply a corrosion protection spray on all met-al, including chrome- and nickel-plated, sur-faces.

5. Use spray oil as a universal cleaner to re-move any remaining dirt.

6. Touch up minor paint damage caused bystones, etc.

7. Wax all painted surfaces.8. Let the motorcycle dry completely before

storing or covering it.

WARNINGEWA19050

Contaminants on the brakes or tires cancause loss of control.• Make sure that there is no oil or wax on the

brakes or tires.• If necessary, clean the brake discs and

brake linings with a regular brake disccleaner or acetone, and wash the tires withwarm water and a mild detergent. Beforeriding at higher speeds, test the motorcy-cle’s braking performance and corneringbehavior.

NOTICEECA24240

• Apply spray oil and wax sparingly andmake sure to wipe off any excess.

• Never apply oil or wax to any rubber andplastic parts, but treat them with a suitablecare product.

• Avoid using abrasive polishing com-pounds as they will wear away the paint.

TIP• Consult a Yamaha dealer for advice on what

products to use.• Washing, rainy weather or humid climates can

cause the headlight lens to fog. Turning theheadlight on for a short period of time will helpremove the moisture from the lens.

EAM30201

STORAGEShort-termAlways store your motorcycle in a cool, dry placeand, if necessary, protect it against dust with aporous cover. Be sure the engine and the ex-haust system are cool before covering the mo-torcycle.

NOTICEECA24250

• Storing the motorcycle in a poorly ventilat-ed room or covering it with a tarp, while it isstill wet, will allow water and humidity toseep in and cause rust.

• To prevent corrosion, avoid damp cellars,stables (because of the presence of ammo-nia) and areas where strong chemicals are


1-25

stored.

Long-termBefore storing your motorcycle for severalmonths: 1. Follow all the instructions in “CARE” on page

1-23.2. Drain the fuel tank, fuel lines, and the carbu-

retor float bowl.3. Perform the following steps to protect the cyl-

inder, piston rings, etc. from corrosion.a. Remove the spark plug, pour a tablespoon

of motor oil in the spark plug hole, and re-install the plug. With the engine stopswitch pushed in, kick the engine overseveral times to coat the cylinder wallswith oil.

4. Lubricate all control cables and the pivotingpoints of all levers and pedals as well as ofthe sidestand.

5. Check and, if necessary, correct the tire airpressure, and then lift the motorcycle so thatboth of its wheels are off the ground. Alterna-tively, turn the wheels a little every month inorder to prevent the tires from becoming de-graded in one spot.

6. Cover the muffler outlet with a plastic bag toprevent moisture from entering it.

TIPMake any necessary repairs before storing themotorcycle.


1-26

1

2

3

4

5

6

7

8

9

10

SPECIFICATIONS

GENERAL SPECIFICATIONS ..........................................................................2-1

ENGINE SPECIFICATIONS..............................................................................2-2

CHASSIS SPECIFICATIONS............................................................................2-5

ELECTRICAL SPECIFICATIONS.....................................................................2-8

TIGHTENING TORQUES..................................................................................2-9GENERAL TIGHTENING TORQUE SPECIFICATIONS ............................2-9ENGINE TIGHTENING TORQUES ..........................................................2-10CHASSIS TIGHTENING TORQUES ........................................................2-11

CABLE ROUTING DIAGRAM ........................................................................2-15

GENERAL SPECIFICATIONS

2-1

EAM20127

GENERAL SPECIFICATIONS

Model Model B1B8

Dimensions Overall length 2140 mm (84.3 in) Overall width 825 mm (32.5 in) Overall height 1285 mm (50.6 in) Seat height 955 mm (37.6 in) Wheelbase 1455 mm (57.3 in) Ground clearance 350 mm (13.78 in)

Weight Curb weight 95 kg (209 lb) Riding capacity 1 person

ENGINE SPECIFICATIONS

2-2

EAM20128


Engine Combustion cycle 2-stroke Cooling system Liquid cooled Induction system Reed valve Displacement 125 cm³ Number of cylinders Single cylinder Bore stroke 54.0 54.5 mm (2.13 2.15 in) Compression ratio 7.4–8.8 : 1 Starting system Kickstarter

Fuel Recommended fuel Premium unleaded gasoline (E10 acceptable) Fuel tank capacity 8.0 L (2.1 US gal, 1.8 Imp.gal) Fuel reserve amount 2.0 L (0.53 US gal, 0.44 Imp.gal)

Engine oil Recommended brand YAMALUBE Lubrication system Premix lubrication Engine oil YAMALUBE 2R Premix ratio 30

Transmission oil Type Motor oil SAE 10W-40 type SG or higher Quantity (disassembled) 0.70 L (0.74 US qt, 0.62 Imp.qt) Quantity 0.66 L (0.70 US qt, 0.58 Imp.qt)

Cooling systemCoolant quantity

Radiator (including all routes) 0.90 L (0.95 US qt, 0.79 Imp.qt) Radiator cap valve opening pressure 93.3–122.7 kPa (0.93–1.23 kgf/cm², 13.5–17.8

psi)

Spark plug(s) Manufacturer/model NGK/BR9EVX Spark plug gap 0.6–0.7 mm (0.024–0.028 in)

Cylinder head Warpage limit 0.03 mm (0.0012 in)

Cylinder Bore 54.000–54.014 mm (2.1260–2.1265 in) Wear limit 54.064 mm (2.1285 in)

Piston Piston-to-cylinder clearance 0.040–0.045 mm (0.0016–0.0018 in) Diameter 53.957–53.972 mm (2.1243–2.1249 in) Measuring point (from piston skirt bottom) 17.5 mm (0.69 in) Piston pin bore inside diameter limit 15.040 mm (0.5921 in) Piston pin outside diameter limit 14.975 mm (0.5896 in) Piston-pin-to-piston-pin-bore clearance 0.008–0.023 mm (0.0003–0.0009 in)

Piston ringTop ring

End gap limit 1.20 mm (0.0472 in) Ring side clearance 0.035–0.070 mm (0.0014–0.0028 in)


2-3

Side clearance limit 0.100 mm (0.0039 in)

Crankshaft Crank assembly width 55.90–55.95 mm (2.201–2.203 in) Runout limit 0.050 mm (0.0020 in)

Clutch Clutch type Wet, multiple-disc Clutch lever free play 7.0–12.0 mm (0.28–0.47 in) Friction plate thickness 2.90–3.10 mm (0.114–0.122 in) Wear limit 2.80 mm (0.110 in) Plate quantity 8 pcs Clutch plate thickness 1.50–1.70 mm (0.059–0.067 in) Plate quantity 7 pcs Warpage limit 0.20 mm (0.008 in) Clutch spring free length 40.10 mm (1.58 in) Clutch spring free length limit 38.10 mm (1.50 in) Push rod bending limit 0.30 mm (0.012 in)

Drivetrain Primary reduction ratio 3.368 (64/19) Transmission type Constant mesh 6-speed

Gear ratio 1st 2.385 (31/13) 2nd 1.933 (29/15) 3rd 1.588 (27/17) 4th 1.353 (23/17) 5th 1.200 (24/20) 6th 1.095 (23/21) Main axle runout limit 0.01 mm (0.0004 in) Drive axle runout limit 0.01 mm (0.0004 in) Secondary reduction ratio 3.846 (50/13) Final drive Chain

Air filter Air filter element Wet element Air filter oil grade Yamaha foam air filter oil or other quality foam

air filter oil

Carburetor Type quantity TMXx38 1 ID mark 1C37 51 Main jet #430 Main air jet ø2.5 Jet needle 6BFY43-74-3 Needle jet S-1 Cutaway 4 Pilot outlet 0.7 Pilot jet #40 Bypass 1 0.7 Bypass 2 0.7 Air screw turns out 2-1/4 Valve seat size 3.8 Starter jet 1 #80 Fuel level (using fuel level gauge) 9.5–10.5 mm (0.37–0.41 in) Throttle grip free play 3.0–5.0 mm (0.12–0.20 in)


2-4

Reed valve Thickness 0.470 mm (0.0185 in) Valve stopper height 8.2–8.6 mm (0.32–0.34 in) Valve bending limit 0.2 mm (0.01 in)

CHASSIS SPECIFICATIONS

2-5

EAM20129


Chassis Frame type Semi double cradle Caster angle 26.8 Trail 116 mm (4.6 in)

Front wheel Wheel type Spoke wheel Rim size 21 x 1.60 Radial wheel runout limit 2.0 mm (0.08 in) Lateral wheel runout limit 2.0 mm (0.08 in) Wheel axle bending limit 0.50 mm (0.02 in)

Rear wheel Wheel type Spoke wheel Rim size 18 x 2.15 Radial wheel runout limit 2.0 mm (0.08 in) Lateral wheel runout limit 2.0 mm (0.08 in) Wheel axle bending limit 0.50 mm (0.02 in)

Front tire Type With tube Size 90/90-21 54M Manufacturer/model DUNLOP/AT81F

Rear tire Type With tube Size 110/90-18 61M Manufacturer/model DUNLOP/AT81

Tire air pressure (measured on cold tires) Front 100 kPa (1.00 kgf/cm², 15 psi) Rear 100 kPa (1.00 kgf/cm², 15 psi)

Front brake Type Hydraulic single disc brake Brake disc thickness limit 2.5 mm (0.10 in) Brake disc runout limit (as measured on

wheel)0.15 mm (0.0059 in)

Brake pad lining thickness limit 1.0 mm (0.04 in) Master cylinder inside diameter 9.52 mm (0.37 in) Caliper cylinder inside diameter (Left) 22.65 mm, 22.65 mm (0.89 in, 0.89 in) Specified brake fluid DOT 4

Rear brake Type Hydraulic single disc brake Brake pedal position 0.0 mm (0.00 in) Brake disc thickness limit 3.5 mm (0.14 in) Brake disc runout limit (as measured on

wheel)0.15 mm (0.0059 in)

Brake pad lining thickness limit 1.0 mm (0.04 in) Master cylinder inside diameter 11.0 mm (0.43 in) Caliper cylinder inside diameter 25.40 mm (1.00 in) Specified brake fluid DOT 4


2-6

Front suspension Type Telescopic fork Spring Coil spring Shock absorber Hydraulic damper Wheel travel 300 mm (11.8 in) Fork spring free length limit 449.0 mm (17.68 in) Inner tube bending limit 0.2 mm (0.01 in) Recommended oil Yamaha Suspension Oil S1 Quantity (left) 425.0 cm³ (14.37 US oz, 14.99 Imp.oz) Quantity (right) 425.0 cm³ (14.37 US oz, 14.99 Imp.oz)

Rebound damping Adjusting system Mechanical adjustable type Unit for adjustment Click Adjustment value from the start position

(Soft)20

Adjustment value from the start position (STD)

11

Adjustment value from the start position (Hard)

0

Compression damping Adjusting system Mechanical adjustable type Unit for compression damping adjustment Click Adjustment value from the start position

(Soft)20


15


0

Rear suspension Type Swingarm (link suspension) Spring Coil spring Shock absorber Gas-hydraulic damper Wheel travel 315 mm (12.4 in)

Spring preload Adjusting system Mechanical adjustable type Adjustment value (Soft) 1.5 mm (0.06 in) Adjustment value (STD) 6.0 mm (0.24 in) Adjustment value (Hard) 18.0 mm (0.71 in)

Rebound damping Adjusting system Mechanical adjustable type Unit for adjustment Click Adjustment value from the start position

(Soft)20


13


0

Compression damping Adjusting system Mechanical adjustable type

Fast compression damping Unit for adjustment Turn


2-7

Adjustment value from the start position (Soft)

2


1-5/8


0

Slow compression damping Unit for adjustment Click Adjustment value from the start position

(Soft)20


13


0

Drive chain Size 520 Chain type Sealed type Number of links 114 Drive chain slack (Maintenance stand) 48.0–58.0 mm (1.89–2.28 in) 15-link length limit 239.3 mm (9.42 in)

ELECTRICAL SPECIFICATIONS

2-8

EAM20130

ELECTRICAL SPECIFICATIONS

Ignition system Ignition system CDI Ignition timing (B.T.D.C.) 0.50 mm (0.02 in) Pickup coil resistance 248.0–372.0 Charging coil 1 resistance 720.0–1080.0 Charging coil 2 resistance 44.0–66.0

Ignition coil Primary coil resistance 0.24–0.36 Secondary coil resistance 5.68–8.52 k

Spark plug cap Resistance 5.00 k

Charging system Charging system CDI magneto

TIGHTENING TORQUES

2-9

EAM20131

TIGHTENING TORQUESEAM30205

GENERAL TIGHTENING TORQUE SPECIFICATIONSThis chart specifies tightening torques for stan-dard fasteners with a standard ISO thread pitch.Tightening torque specifications for special com-ponents or assemblies are provided for eachchapter of this manual. To avoid warpage, tight-en multi-fastener assemblies in a crisscross pat-tern and progressive stages until the specifiedtightening torque is reached. Unless otherwisespecified, tightening torque specifications re-quire clean, dry threads. Components should beat room temperature.

A. Distance between flatsB. Outside thread diameter

A (nut) B (bolt)General tightening torques

N·m kgf·m lb·ft

10 mm 6 mm 6 0.6 4.4

12 mm 8 mm 15 1.5 11

14 mm 10 mm 30 3.0 22

17 mm 12 mm 55 5.5 41

19 mm 14 mm 85 8.5 63

22 mm 16 mm 130 13.0 96

TIGHTENING TORQUES

2-10

EAM30203

ENGINE TIGHTENING TORQUESTIP- marked portion shall be checked for torque tightening after break-in or before each race.

Item Thread size Q’ty Tightening torques Remarks

Spark plug M14S 1 20 N·m (2.0 kgf·m, 15 lb·ft)

Cylinder head nut M8 5 28 N·m (2.8 kgf·m, 21 lb·ft)

Cylinder head stud bolt M8 5 13 N·m (1.3 kgf·m, 9.6 lb·ft)

Cylinder nut M8 4 30 N·m (3.0 kgf·m, 22 lb·ft)

Cylinder stud bolt M10 4 13 N·m (1.3 kgf·m, 9.6 lb·ft)

Power valve cover screw M5 4 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Power valve link lever bolt M4 1 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

Power valve M5 4 8 N·m (0.8 kgf·m, 5.9 lb·ft)

Push rod bolt M5 1 4.5 N·m (0.45 kgf·m, 3.3 lb·ft)

Thrust plate screw M5 1 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

Governor fork screw M4 2 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Power valve housing bolt M5 3 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

Water pump housing cover bolt M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Coolant drain bolt M6 1 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Radiator bolt M6 6 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Radiator guard bolt M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Radiator hose clamp M6 8 1.5 N·m (0.15 kgf·m, 1.1 lb·ft)

Air filter element M6 1 2.0 N·m (0.20 kgf·m, 1.5 lb·ft)

Carburetor joint bolt M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Carburetor joint clamp M4 1 2.3 N·m (0.23 kgf·m, 1.7 lb·ft)

Air filter case joint clamp M4 1 2.3 N·m (0.23 kgf·m, 1.7 lb·ft)

Air filter case bolt M6 2 8 N·m (0.8 kgf·m, 5.9 lb·ft)

Air filter guide clamp M5 1 3.5 N·m (0.35 kgf·m, 2.6 lb·ft)

Reed valve screw M3 6 1.0 N·m (0.10 kgf·m, 0.73 lb·ft)

Locknut (throttle cable handlebar side) M8 1 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Locknut (throttle cable carburetor side) M6 1 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

Crankcase bolt M6 12 14 N·m (1.4 kgf·m, 10 lb·ft)

Crankcase cover screw (right) M6 8 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Crankcase cover screw (left) M6 4 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Drive sprocket cover screw M6 2 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Bearing plate cover screw M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Holder bolt M6 1 10 N·m (1.0 kgf·m, 7.4 lb·ft)

LT

LT

TIGHTENING TORQUES

2-11

EAM30204

CHASSIS TIGHTENING TORQUESTIP- marked portion shall be checked for torque tightening after break-in or before each race.

Oil check bolt M6 1 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Oil drain bolt M10 1 20 N·m (2.0 kgf·m, 15 lb·ft)

Kickstarter lever M6 1 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Clutch cover bolt M6 6 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Primary drive gear bolt M8 1 48 N·m (4.8 kgf·m, 35 lb·ft)

Clutch boss nut M16 1 80 N·m (8.0 kgf·m, 59 lb·ft) Use a lock washer.

Clutch spring bolt M6 5 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Locknut (clutch cable side) M6 1 4.3 N·m (0.43 kgf·m, 3.2 lb·ft)

Drive sprocket nut M18 1 75 N·m (7.5 kgf·m, 55 lb·ft) Use a lock washer.

Shift pedal bolt M6 1 12 N·m (1.2 kgf·m, 8.9 lb·ft)

Bearing plate cover screw (shift cam) M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Shift guide bolt M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Stopper lever bolt M6 1 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Segment M8 1 30 N·m (3.0 kgf·m, 22 lb·ft)

Exhaust pipe bolt M6 2 12 N·m (1.2 kgf·m, 8.9 lb·ft)

Exhaust pipe stay bolt (front) M6 1 12 N·m (1.2 kgf·m, 8.9 lb·ft)

Exhaust pipe stay bolt (rear) M6 1 12 N·m (1.2 kgf·m, 8.9 lb·ft)

Silencer bolt M6 1 12 N·m (1.2 kgf·m, 8.9 lb·ft) /

Fiber bolt M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Stator coil screw M6 3 7 N·m (0.7 kgf·m, 5.2 lb·ft)

CDI magneto rotor nut M12 1 56 N·m (5.6 kgf·m, 41 lb·ft)

Ignition coil bolt M6 2 7 N·m (0.7 kgf·m, 5.2 lb·ft)


Upper bracket pinch bolt M8 4 21 N·m (2.1 kgf·m, 15 lb·ft)

Lower bracket pinch bolt M8 4 21 N·m (2.1 kgf·m, 15 lb·ft)

Steering stem nut M24 1 145 N·m (14.5 kgf·m, 107 lb·ft)

Upper handlebar holder bolt M8 4 28 N·m (2.8 kgf·m, 21 lb·ft)

Lower handlebar holder nut M12 2 40 N·m (4.0 kgf·m, 30 lb·ft)

Steering ring nut M28 1 Refer to TIP.

Damper assembly (front fork) M51 2 30 N·m (3.0 kgf·m, 22 lb·ft)


LT

LT

LT

LT

LT

TIGHTENING TORQUES

2-12

Inner tube and adjuster M22 2 55 N·m (5.5 kgf·m, 41 lb·ft)

Base valve (front fork) M42 2 29 N·m (2.9 kgf·m, 21 lb·ft)

Adjuster (damper assembly) M12 2 29 N·m (2.9 kgf·m, 21 lb·ft)

Bleed screw (front fork) M5 2 1.3 N·m (0.13 kgf·m, 0.95 lb·ft)

Front fork protector bolt M6 6 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Cable guide screw M6 1 3.8 N·m (0.38 kgf·m, 2.8 lb·ft)

Front brake hose holder bolt M6 2 9 N·m (0.9 kgf·m, 6.6 lb·ft)

Throttle cable cap screw M4 2 0.5 N·m (0.05 kgf·m, 0.37 lb·ft)

Front brake master cylinder holder bolt M6 2 9 N·m (0.9 kgf·m, 6.6 lb·ft)

Front brake lever pivot bolt M6 1 6 N·m (0.6 kgf·m, 4.4 lb·ft)

Front brake lever pivot nut M6 1 6 N·m (0.6 kgf·m, 4.4 lb·ft)

Locknut (front brake lever position) M6 1 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Clutch lever nut M6 1 4.8 N·m (0.48 kgf·m, 3.5 lb·ft)

Clutch lever holder bolt M6 2 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Locknut (clutch lever position) M5 1 5 N·m (0.5 kgf·m, 3.7 lb·ft)

Front brake master cylinder reservoir cap screw M4 2 1.5 N·m (0.15 kgf·m, 1.1 lb·ft)

Front brake hose union bolt M10 1 30 N·m (3.0 kgf·m, 22 lb·ft)

Front brake caliper bolt M8 2 28 N·m (2.8 kgf·m, 21 lb·ft)

Grip cap bolt M6 2 3.8 N·m (0.38 kgf·m, 2.8 lb·ft)

Engine stop switch screw M3 1 0.5 N·m (0.05 kgf·m, 0.37 lb·ft)

Brake pad pin plug M10 2 2.5 N·m (0.25 kgf·m, 1.8 lb·ft)

Brake pad pin M10 2 17 N·m (1.7 kgf·m, 13 lb·ft)

Brake caliper bleed screw M8 2 6 N·m (0.6 kgf·m, 4.4 lb·ft)

Front wheel axle nut M16 1 105 N·m (10.5 kgf·m, 77 lb·ft)

Front wheel axle pinch bolt M8 4 21 N·m (2.1 kgf·m, 15 lb·ft)

Front brake disc bolt M6 6 12 N·m (1.2 kgf·m, 8.9 lb·ft) /

Rear brake disc bolt M6 6 12 N·m (1.2 kgf·m, 8.9 lb·ft) /

Footrest bracket bolt M10 4 55 N·m (5.5 kgf·m, 41 lb·ft)

Rear brake pedal bolt M8 1 26 N·m (2.6 kgf·m, 19 lb·ft)

Rear brake master cylinder bolt M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Rear brake master cylinder reservoir cap bolt M4 2 1.5 N·m (0.15 kgf·m, 1.1 lb·ft)

Rear brake hose union bolt M10 1 30 N·m (3.0 kgf·m, 22 lb·ft)

Rear brake pedal adjusting locknut M6 1 6 N·m (0.6 kgf·m, 4.4 lb·ft)

Rear wheel axle nut M20 1 125 N·m (12.5 kgf·m, 92 lb·ft)


LT

LT

LT

LT

TIGHTENING TORQUES

2-13

Nipple (spoke) — 72 2.5 N·m (0.25 kgf·m, 1.8 lb·ft)

Rear wheel sprocket nut M8 6 42 N·m (4.2 kgf·m, 31 lb·ft)

Rear brake disc cover bolt M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Rear brake caliper protector bolt M6 2 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Drive chain puller locknut M8 2 19 N·m (1.9 kgf·m, 14 lb·ft)

Engine mounting nut (front side) M10 1 64 N·m (6.4 kgf·m, 47 lb·ft)

Engine mounting nut (lower side) M10 1 64 N·m (6.4 kgf·m, 47 lb·ft)

Engine bracket nut (upper side) M8 2 34 N·m (3.4 kgf·m, 25 lb·ft)

Engine bracket nut (lower side) M8 1 34 N·m (3.4 kgf·m, 25 lb·ft)

Pivot shaft nut M16 1 85 N·m (8.5 kgf·m, 63 lb·ft)

Relay arm nut (swingarm side) M14 1 70 N·m (7.0 kgf·m, 52 lb·ft)

Connecting arm nut (relay arm side) M14 1 80 N·m (8.0 kgf·m, 59 lb·ft)

Connecting arm nut (frame side) M14 1 80 N·m (8.0 kgf·m, 59 lb·ft)

Rear shock absorber assembly upper nut M10 1 56 N·m (5.6 kgf·m, 41 lb·ft)

Rear shock absorber assembly lower nut M10 1 53 N·m (5.3 kgf·m, 39 lb·ft)

Rear frame bolt (upper) M8 1 32 N·m (3.2 kgf·m, 24 lb·ft)

Rear frame bolt (lower) M8 2 29 N·m (2.9 kgf·m, 21 lb·ft)

Brake hose holder screw M5 4 3.5 N·m (0.35 kgf·m, 2.6 lb·ft)

Swingarm and patch screw M4 4 2.0 N·m (0.20 kgf·m, 1.5 lb·ft)

Drive chain tensioner bolt M8 1 16 N·m (1.6 kgf·m, 12 lb·ft)

Drive chain tensioner nut M8 1 16 N·m (1.6 kgf·m, 12 lb·ft)

Drive chain support bolt M6 1 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Drive chain support nut M6 2 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Drive chain guide bolt M5 4 6 N·m (0.6 kgf·m, 4.4 lb·ft)

Fuel tank bolt (boss) M10 2 20 N·m (2.0 kgf·m, 15 lb·ft) /

Fuel tank bolt M6 2 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Fuel cock screw M6 2 4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

Fuel tank screw (seat set side) M6 1 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Fuel tank screw (fitting band side) M6 1 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Fuel tank bracket bolt M6 4 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Air scoop bolt (fuel tank) M6 4 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Air scoop bolt (radiator guard) M6 2 6 N·m (0.6 kgf·m, 4.4 lb·ft)

Front fender bolt M6 4 10 N·m (1.0 kgf·m, 7.4 lb·ft)

Rear fender bolt (front side) M6 2 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Rear fender bolt (rear side) M6 2 12 N·m (1.2 kgf·m, 8.9 lb·ft) /


LT

LT

LT

TIGHTENING TORQUES

2-14

TIPSteering ring nut1. First, tighten the steering ring nut approximately 38 N·m (3.8 kgf·m, 28 lb·ft) by using the steering nut

wrench, then loosen the steering ring nut one turn.2. Retighten the steering ring nut 7 N·m (0.7 kgf·m, 5.2 lb·ft).

Screw (mud flap) — 2 1.3 N·m (0.13 kgf·m, 0.95 lb·ft)

Side cover bolt M6 2 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Seat bolt M8 2 19 N·m (1.9 kgf·m, 14 lb·ft)

Number plate bolt M6 1 7 N·m (0.7 kgf·m, 5.2 lb·ft)

Sidestand bolt M10 1 25 N·m (2.5 kgf·m, 18 lb·ft)


CABLE ROUTING DIAGRAM

2-15

EAM20152

CABLE ROUTING DIAGRAMFrame and engine (left side view)


2-16

1. Engine stop switch lead2. Throttle cable3. Clutch cable4. Ground lead5. High tension cord6. Clamp7. Air vent hose8. Radiator breather hose9. CDI magneto lead10.YPVS breather hose11.Engine bracket (right)12.Engine bracket (left)13.Crankcase breather hose14.Overflow hose15.Connector cover

A. Pass the clutch cable on the outside of the throttle cable and engine stop switch lead. Either the throttle cable or the engine stop switch lead can be routed on the outside.

B. Align the throttle cable locating tape with the cable guide. Fasten each part with the plastic locking tie.

C. Pass the throttle cable, clutch cable and engine stop switch lead above the radiator hose.

D. Install the ignition coil, side core and ground lead together to the frame. Take care to fas-ten the ground lead so that its terminal is within the indicated range.

E. Clamp the throttle cable and high tension cord to the frame. Position the lock portion under the frame.

F. Clamp the clutch cable to the left engine bracket. The lock portion should face the inner side of the vehicle, while the end should face the rear side of the vehicle. Clamp the clutch cable below the positioning grommet.

G. Pass the air vent hose back of the throttle cable.

H. Pass the air vent hose, overflow hose and crankcase breather hose between the frame and connecting rod.

I. Pass the radiator breather hose and YPVS breather hose outside the engine bracket and inside the down tube. Then pass the radiator breather hose inside the YPVS breather hose.

J. Clamp the CDI magneto lead, radiator breather hose and YPVS breather hose to the frame.

K. Clamp to the frame the CDI magneto lead and radiator breather hose. Pay attention so that the radiator breather hose is not crushed when installing the clamp. Position the end of the clamp inside the radiator breather hose. Take care to clamp them above the projection on the frame.

L. Locate the clamp ends in the arrowed range.M. Direct the clip with its finger grip facing for-

ward.

N. Tighten the clamp with its bolt head facing the left side of the chassis (on both sides of the carburetor joint and the air filter joint).

O. Pass the air vent hose, overflow hose and crankcase breather hose so that they do not contact the rear shock absorber.

P. After connecting the coupler, make sure that the connector cover contacts the end of the coupler.


2-17

Frame and engine (right side view)


2-18

1. High tension cord2. Engine stop switch lead3. Ignition coil lead4. Clamp5. CDI unit6. CDI unit band7. Joint connector8. Radiator breather hose9. CDI magneto lead10.Connector cover11.Throttle cable12.Clutch cable13.CDI unit stay

A. Pass the high tension cord to the left of the radiator hose.

B. Using a plastic locking tie, clamp the engine stop switch lead, ignition coil lead and CDI magneto lead together with the clamp ends backward and then cut off the tie end.

C. Clamp to the frame the throttle cable, clutch cable, ignition coil lead and engine stop switch lead. In so doing, clamp the ignition coil lead and engine stop switch lead at their protecting tubes.

D. Face the joint connector with its open end downward, and there is no pinching with peripheral parts.

E. Pass the CDI magneto lead and radiator breather hose between the frame and the radiator (right).

F. Clamp the CDI magneto lead to the frame at its locating tape.

G. After connecting the coupler, make sure that the connector cover contacts the end of the coupler.

H. Locate the clamp ends in the arrowed range.I. Insert the CDI unit band until it stops at the

CDI unit stay.J. Pass the CDI magneto lead and radiator

breather hose between the frame and the radiator hose so that they come within the arrow- indicated range. Also take care so that the CDI magneto lead passes on the left of the radiator breather hose.


2-19

Handlebar (front view)

(0 in)0 mm

0 mm

(0 in)


2-20

1. Brake hose2. Master cylinder3. Engine stop switch lead4. Engine stop switch5. Throttle cable6. Clutch cable7. Clamp8. Cable guide

A. Install the brake hose so that its pipe portion directs as shown and lightly touches the pro-jection on the master cylinder.

B. Pass the engine stop switch lead in the mid-dle of the clutch holder.

C. Clamp the engine stop switch lead to the handlebar.

D. Pass the brake hose in front of the number plate and through the cable guide.

E. Pass the clutch cable through the cable guide on the number plate.


2-21

Rear brake (right side view)


2-22

1. Master cylinder2. Brake hose holder3. Brake hose

A. Pass the brake hose into the brake hose holders.

B. If the brake hose contacts the rear shock absorber spring, correct its twist.

C. Install the brake hose so that its pipe portion directs as shown and lightly touches the pro-jection on the master cylinder.


2-23

1

2

3

4

5

6

7

8

9

10

PERIODIC CHECKS AND ADJUSTMENTS

MAINTENANCE INTERVALS ...........................................................................3-1MAINTENANCE INTERVALS.....................................................................3-1

PRE-OPERATION INSPECTION AND MAINTENANCE .................................3-4GENERAL INSPECTION AND MAINTENANCE........................................3-4

ENGINE.............................................................................................................3-5ADJUSTING THE PILOT AIR SCREW ......................................................3-5CHECKING THE ENGINE IDLING SPEED................................................3-5CHECKING THE THROTTLE GRIP...........................................................3-5CHECKING THE SPARK PLUG.................................................................3-5CHECKING THE TRANSMISSION OIL LEVEL .........................................3-6CHANGING THE TRANSMISSION OIL .....................................................3-6ADJUSTING THE CLUTCH LEVER FREE PLAY ......................................3-7ADJUSTING THE CLUTCH LEVER POSITION.........................................3-8CLEANING THE AIR FILTER ELEMENT...................................................3-8CHECKING THE CARBURETOR JOINT ...................................................3-9CHECKING THE CARBURETOR HOSES.................................................3-9CHECKING THE EXHAUST SYSTEM.....................................................3-10CHECKING THE COOLANT LEVEL ........................................................3-11CHECKING THE COOLING SYSTEM .....................................................3-11CHANGING THE COOLANT....................................................................3-11

CHASSIS ........................................................................................................3-13ADJUSTING THE FRONT DISC BRAKE .................................................3-13ADJUSTING THE REAR DISC BRAKE ...................................................3-13CHECKING THE BRAKE FLUID LEVEL..................................................3-14CHECKING THE FRONT BRAKE PADS .................................................3-14CHECKING THE REAR BRAKE PADS....................................................3-15CHECKING THE FRONT BRAKE HOSE.................................................3-15CHECKING THE REAR BRAKE HOSE ...................................................3-15CHECKING THE BRAKE OPERATION ...................................................3-15BLEEDING THE HYDRAULIC BRAKE SYSTEM.....................................3-15DRIVE CHAIN SLACK..............................................................................3-16LUBRICATING THE DRIVE CHAIN .........................................................3-17CHECKING AND ADJUSTING THE STEERING HEAD ..........................3-17LUBRICATING THE STEERING HEAD ...................................................3-18CHECKING THE FRONT FORK LEGS....................................................3-18ADJUSTING THE FRONT FORK LEGS ..................................................3-19CHECKING THE REAR SHOCK ABSORBER ASSEMBLY.....................3-20ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLY ...................3-21CHECKING THE SWINGARM OPERATION ...........................................3-23LUBRICATING THE SWINGARM PIVOT ................................................3-23CHECKING THE CONNECTING ARM AND RELAY ARM ......................3-23CHECKING THE TIRES ...........................................................................3-23CHECKING AND TIGHTENING THE SPOKES .......................................3-23CHECKING THE WHEELS ......................................................................3-24CHECKING THE WHEEL BEARINGS .....................................................3-24

CHECKING THE CHASSIS FASTENERS ...............................................3-24CHECKING AND LUBRICATING THE CABLES......................................3-24LUBRICATING THE BRAKE LEVER .......................................................3-24LUBRICATING THE CLUTCH LEVER .....................................................3-24LUBRICATING THE PEDAL.....................................................................3-24CHECKING THE SIDESTAND .................................................................3-25LUBRICATING THE SIDESTAND............................................................3-25

ELECTRICAL SYSTEM..................................................................................3-26CHECKING THE IGNITION TIMING ........................................................3-26

MAINTENANCE INTERVALS

3-1

EAM20157

MAINTENANCE INTERVALSEAM30369


NOTICEECA25871

• After a break-in or before each race, always check the points shown in “TORQUE-CHECKPOINTS” for tightening torques and retighten them.

• Periodic inspection is essential in making full use of the machine performance. The life ofparts varies significantly according to the environment in which the machine runs (e.g., rain,dirt, etc.). Therefore, earlier inspection is required by reference to the list below.

TIPItems marked with an asterisk should be performed by a Yamaha dealer as they require special tools,data and technical skills.

No. Item Routine After break-in

Every race

(about 2.5 hours)

Every third race (about 7.5

hours)

Every fifth race

(about 12.5 hours)

As required

1 * Piston

• Check piston for carbon deposits and cracks or damage.

• Clean.

• Replace.

2 * Piston rings

• Check piston ring end gap and rings for damage.

• Replace.

3 * Piston pin and small end bearing

• Check piston pin and small end bearing for damage.

• Replace.

4 * Cylinder head

• Check cylinder head for carbon deposits.

• Clean.

• Check cylinder head gasket for damage.

• Tighten cylinder head nuts if nec-essary.

• Replace cylinder head gasket.

5 * Cylinder

• Check cylinder for score marks or wear.

• Clean.

• Replace.

6 * YPVS

• Check YPVS for carbon deposits and cracks or damage.

• Clean.

7 * Clutch

• Check clutch housing, friction plates, clutch plates and clutch springs for wear or damage.

• Adjust.

• Replace.

8 * Transmission

• Change the transmission oil.

• Check transmission for damage.

• Replace bearings.

9 * Shift forks, guide bars, shift cam

• Check all parts for wear and dam-age.

• Replace if necessary.


3-2

10 * Rotor nut (flywheel magneto)

• Tighten.

11 * Kickstarter system • Check idle gear for damage.• Replace if necessary.

12 * Exhaust system

• Check exhaust pipe and muffler for carbon deposits.

• Clean.

13 * Crankshaft

• Check crankshaft for carbon deposits and damage.

• Clean.

14 * Carburetor

• Check carburetor settings and for obstructions.

• Adjust and clean.

15 Spark plug

• Check condition.• Clean and regap.

• Replace.

16 * Drive chain

• Check chain slack, alignment and condition.

• Adjust and thoroughly lubricate chain with Yamaha chain and cable lube or equivalent.

• Replace.

17 * Cooling system

• Check coolant level and for leak-age.

• Check hoses for cracks or dam-age.

• Check radiator cap spring opera-tion.

• Change coolant. Every 2 years

18 * Chassis fasteners• Check all chassis fitting and fas-

teners.• Correct or tighten if necessary.

19 Air filter element• Clean.

• Replace.

20 * Frame • Clean and check for damage.

21 * Fuel line • Clean and check for leakage.

22 * Brakes

• Adjust lever position and pedal position.

• Lubricate pivot points.• Check brake disk surface.• Check fluid level and for leakage.• Tighten brake disk bolts, caliper

bolts, master cylinder bolts and union bolts.

• Replace brake pads.

• Replace brake fluid. Every year


Every race

(about 2.5 hours)


hours)

Every fifth race

(about 12.5 hours)

As required


3-3

23 * Front fork

• Check operation and for oil leak-age.

• Adjust if necessary.• Clean dust seal and lubricate with

lithium-soap-based grease.

• Replace fork oil.

• Replace oil seals.

• Replace protector seal.

24 * Shock absorber assembly

• Check operation and adjust.• Tighten if necessary.

• Lubricate with lithium-soap-based grease.

(After

washing the motor-cycle or riding in the rain)

25 * Drive chain roller and support guide

• Check for wear or damage.• Replace if necessary.

26 * Rear suspension

• Check operation and tighten if necessary.

• Lubricate with molybdenum disul-fide grease.

27 * Swingarm pivot bear-ings

• Check bearing assemblies for looseness.

• Lubricate with molybdenum disul-fide grease.

28 Sidestand • Lubricate with lithium-soap-based grease.

29 * Steering head

• Check operation, free play, and tighten if necessary.

• Clean and lubricate with lithium-soap-based grease.

• Replace bearings.

30 * Tires and wheels

• Check tire air pressure, wheel runout, spokes for looseness, and tires for wear.

• Tighten sprocket bolts if neces-sary.

• Check wheel bearings for loose-ness.

• Lubricate wheel bearings with lith-ium-soap-based grease.

• Replace wheel bearings.

31 * Moving parts and cables

• Lubricate.

32 * Throttle grip

• Check operation.• Check throttle grip free play, and

adjust if necessary.• Lubricate cable and grip housing.


Every race

(about 2.5 hours)


hours)

Every fifth race

(about 12.5 hours)

As required

PRE-OPERATION INSPECTION AND MAINTENANCE

3-4

EAM20134

PRE-OPERATION INSPECTION AND MAINTENANCEBefore riding for break-in operation, practice or a race, make sure the machine is in good operating con-dition.Before using this machine, check the following points.

EAM30209

GENERAL INSPECTION AND MAINTENANCE

TIPPerform usual maintenance enough so that, in the race course, a confirmation of that and simple settingadjustments may only be left, in order to get enough time to use effectively.

Item Inspect Page

Coolant Check that coolant is filled up to the radiator cap.Check the cooling system for leakage.

3-11, 3-11, 3-11, 6-3, 6-3

Fuel Check that a fresh gasoline is filled in the fuel tank.Check the fuel line for leakage. 1-18

Transmission oil Check that the oil level is correct. Check the crankcase for leakage. 3-6, 3-6

Gear shifter and clutch Check that gears can be shifted correctly in order and that the clutch operates smoothly. 3-7, 3-8

Throttle grip/HousingCheck that the throttle grip operation and free play are cor-rectly adjusted. Lubricate the throttle grip and housing, if necessary.

3-5, 3-24

Brakes Check the play of front brake and effect of front and rear brake.

3-13, 3-13, 3-14, 3-14, 3-15, 3-15,

3-15, 3-15

Drive chain Check drive chain slack and alignment. Check that the drive chain is lubricated properly. 3-16, 4-64, 4-64

Wheels Check for excessive wear and tire pressure. Check for loose spokes and have no excessive play.

3-23, 3-23, 3-24, 3-24

Steering Check that the handlebar can be turned smoothly and have no excessive play. 3-17

Front forks and rear shock absorber

Check that they operate smoothly and there is no oil leak-age.

3-18, 3-19, 3-20, 3-21, 3-23

Cables (wires)Check that the clutch and throttle cables move smoothly. Check that they are not caught when the handlebars are turned or when the front forks travel up and down.

—

Exhaust pipe Check that the exhaust pipe is tightly mounted and has no cracks. 3-10

Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose.

4-8, 4-8, 4-8, 4-8, 4-9, 4-9

Lubrication Check for smooth operation. Lubricate if necessary. 3-24, 3-24, 3-24, 3-24

Bolts and nuts Check the chassis and engine for loose bolts and nuts. 1-21

Lead connectors Check that the stator coil assembly, ECU and ignition coil are connected tightly. 1-10

Settings

Is the machine set suitably for the condition of the racing course and weather or by taking into account the results of test runs before racing? Are inspection and maintenance completely done?

10-8, 10-8, 10-8, 10-9, 10-9, 10-10,

10-10, 10-11, 10-11, 10-13, 10-14

ENGINE

3-5

EAM20135

ENGINEEAM30607

ADJUSTING THE PILOT AIR SCREW1. Adjust:

• Pilot air screw “1”

TIPTo optimize the fuel flow at a smaller throttleopening, each vehicle’s pilot air screw has beenindividually set at the factory. Before adjustingthe pilot air screw, turn it in fully and count thenumber of turns. Record this number as the fac-tory-set number of turns out.

a. Turn in the pilot air screw until it is lightlyseated.

b. Turn out the pilot air screw to the factory-set number of turns.

EAM30412

CHECKING THE ENGINE IDLING SPEED1. Start the engine and thoroughly warm it up.2. Adjust:

• Engine idling speeda. Loosen the locknut “1”.b. Turn the throttle stop screw “2” until the

engine runs at the lowest possible speed.

c. Tighten the locknut.

EAM30475

CHECKING THE THROTTLE GRIPTIPPrior to adjusting throttle grip free play, the en-gine idling speed should be adjusted.

1. Check:• Throttle grip free play “a”

Out of specification Regulate.

2. Adjust:• Throttle grip free play

a. Slide the adjuster cover.b. Loosen the locknut “1”.c. Turn the adjuster “2” until the specified

free play is obtained.d. Tighten the locknut.

WARNINGEWA18470

After adjusting the throttle grip free play,start the engine and turn the handlebar to theright and to the left to ensure that this doesnot cause the engine idling speed to change.

EAM30254

CHECKING THE SPARK PLUG1. Disconnect:

• Spark plug cap2. Remove:

• Spark plug

Air screw turns out2-1/4

Throttle grip free play3.0–5.0 mm (0.12–0.20 in)

a

G088895

ENGINE

3-6

NOTICEECA13330

Before removing the spark plug, blow awayany dirt accumulated in the spark plug wellwith compressed air to prevent it from fallinginto the cylinder.

3. Check:• Spark plug type

Incorrect Change.

4. Check:• Electrode “1”

Damage/wear Replace the spark plug.• Insulator “2”

Abnormal color Replace the spark plug.Normal color is medium-to-light tan.

5. Clean:• Spark plug

(with a spark plug cleaner or wire brush)6. Measure:

• Spark plug gap “a”(with a wire thickness gauge)Out of specification Regap.

7. Install:• Spark plug

TIPBefore installing the spark plug, clean the sparkplug and gasket surface.

8. Connect:• Spark plug cap

EAM30539

CHECKING THE TRANSMISSION OIL LEVEL1. Start the engine, warm it up for several min-

utes and wait for five minutes.2. Place the machine on a level place and hold

it up on upright position by placing the main-tenance stand under the engine.

3. Check:• Transmission oil level

a. Remove the oil check bolt “1”.b. Inspect the oil level.

TIPBe sure the machine is positioned straight upwhen inspecting the oil level.

WARNINGEWA21090

Never attempt to remove the oil check boltjust after high speed operation. The heatedoil could spout out, causing danger. Wait un-til the oil cools down.

Oil flows out Oil level is correct.Oil does not flow out Oil level is low.Add transmission oil until oil flows out.

c. Inspect the gasket (oil check bolt), replaceif damaged.

d. Tighten the oil check bolt.

EAM30540

CHANGING THE TRANSMISSION OIL1. Start the engine and warm it up for several

minutes and wait for five minute.2. Place the machine on a level place and hold

it on upright position by placing the mainte-nance stand under the engine.

3. Place a suitable container under the engine.

Manufacturer/modelNGK/BR9EVX

Spark plug gap0.6–0.7 mm (0.024–0.028 in)

Spark plug20 N·m (2.0 kgf·m, 15 lb·ft)

G088879

TR..

TypeMotor oil SAE 10W-40 type SG or higher

Quantity (disassembled)0.70 L (0.74 US qt, 0.62 Imp.qt)

Quantity0.66 L (0.70 US qt, 0.58 Imp.qt)

Oil check bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)T

R..

ENGINE

3-7

4. Remove:• Oil drain bolt “1”• Oil filler cap “2”

5. Drain:• Transmission oil

6. Install:• Aluminum washer • Oil drain bolt

7. Fill:• Transmission oil

8. Check:• Oil leakage

9. Check:• Transmission oil level

10.Install:• Oil filler cap

EAM30216

ADJUSTING THE CLUTCH LEVER FREE PLAY1. Check:

• Clutch lever free play “a”


2. Adjust:• Clutch lever free play

Handlebar sidea. Turn the adjuster “1” until the specified

clutch lever free play is obtained.

TIPIf the clutch lever free play cannot be obtainedon the handlebar side, use the adjuster on theclutch cable side.

Clutch cable sidea. Slide the clutch cable cover.b. Loosen the locknut “1”.c. Turn the adjuster “2” until the specified

clutch lever free play is obtained.d. Tighten the locknut “1”.

e. Return the clutch cable cover to its originalposition.

Oil drain bolt20 N·m (2.0 kgf·m, 15 lb·ft)

TypeMotor oil SAE 10W-40 type SG or higher

Quantity (disassembled)0.70 L (0.74 US qt, 0.62 Imp.qt)

Quantity0.66 L (0.70 US qt, 0.58 Imp.qt)

New

TR..

Clutch lever free play7.0–12.0 mm (0.28–0.47 in)

Locknut (clutch cable side)4.3 N·m (0.43 kgf·m, 3.2 lb·ft)

a

G088887

TR..

ENGINE

3-8

EAM30370

ADJUSTING THE CLUTCH LEVER POSITION1. Adjust:

• Clutch lever position “a” Loosen the locknut “1” and use the adjuster“2” to adjust the clutch lever position “a” asdesired.

2. Tighten:• Locknut

EAM30219

CLEANING THE AIR FILTER ELEMENT1. Remove:

• SeatRefer to “GENERAL CHASSIS” on page 4-1.

2. Remove:• Fitting bolt “1”• Washer “2”• Air filter element “3”• Air filter guide “4”

NOTICEECA14401

Never operate the engine without the air filterelement installed. Unfiltered air will causerapid wear of engine parts and may damagethe engine. Operating the engine without theair filter element will also affect carburetorsynchronization, leading to poor engine per-formance and possible overheating.

3. Wash:• Air filter element

a. After washing the element with air filtercleaner or kerosene, squeeze and dry itcompletely.

WARNINGEWA19110

Do not use gasoline or organic (acid/alka-line) volatile oil for washing.

NOTICEECA24280

Do not twist the element when squeezing theelement.

4. Check:• Air filter element

Damage Replace.5. Apply:

Yamaha foam air filter oil or other qualityfoam air filter oil.a. Put the air filter element into a plastic bag

and drip the filter oil into the bag.b. With the element inside the bag, rub it

thoroughly so that the element is evenlypermeated with the oil.

c. Wrap the element in a clean cloth, rub theelement gently, and wipe off any excessoil.

TIP• The element should be permeated with oil so

that it is wet but not dripping.• When replacing the element, permeate the el-

ement in oil by using the same procedure aswhen cleaning.

Locknut (clutch lever position)5 N·m (0.5 kgf·m, 3.7 lb·ft)T

R..

ENGINE

3-9

6. Install:• Air filter guide “1”

TIPAlign the projection “a” on filter guide with thehole “b” in air filter element.

7. Apply:• Lithium soap base grease

(on the matching surface “a” on air filter ele-ment)

8. Install:• Air filter element “1”• Washer• Fitting bolt

TIPAlign the projection “a” on filter guide with thehole “b” in air filter case.

NOTICEECA26420

Make sure that the air filter element is prop-erly seated in the air filter case. The engineshould never be operated without the air fil-ter element installed, otherwise the piston(s)and/or cylinder(s) may become excessivelyworn.

EAM30541

CHECKING THE CARBURETOR JOINT1. Check:

• Carburetor joint “1”Cracks/damage Replace.

EAM30542

CHECKING THE CARBURETOR HOSESThe following procedure applies to all of the fueland vacuum hoses.1. Check:

• Fuel hose• Carburetor breather hose “1”• Overflow hose “2”

Cracks/damage Replace.Loose connection Connect properly.

Fitting bolt2.0 N·m (0.20 kgf·m, 1.5 lb·ft)

a

TR..

1

ENGINE

3-10

EAM30221

CHECKING THE EXHAUST SYSTEM1. Remove:

• Exhaust pipe• Silencer

Refer to “ENGINE REMOVAL” on page 5-1.2. Check:

• Exhaust pipe• Silencer

Crack/damage Replace.Refer to “ENGINE REMOVAL” on page 5-1.

3. Check:• Silencer fiber

Damage Replace.4. Replace:

• Silencer fibera. Remove the silencer bolts “1”, silencer “2”

and fiber bolts “3”.TIPRemove the inner pipe while holding the silencerin place with a vise etc.

b. Remove the inner pipe “1”.c. Replace the fiber “2”.d. Install the inner pipe.

TIPApply heat-resistant sealant to the areas shown,making sure that there are no gaps in the beadsof sealant.

5. Check:• Gasket “1”

Damage Replace.Refer to “ENGINE REMOVAL” on page 5-1.

TIPInstall the gaskets with their depressed “a” fac-ing outward.

6. Check:• Tightening torques

1

1

1

2

Fiber bolt “1”10 N·m (1.0 kgf·m, 7.4 lb·ft)LOCTITE®

Silencer bolt “2”12 N·m (1.2 kgf·m, 8.9 lb·ft)LOCTITE®

Side cover bolt7 N·m (0.7 kgf·m, 5.2 lb·ft)

New

TR..

LT

LT

2

2

111

ENGINE

3-11

EAM30210

CHECKING THE COOLANT LEVEL

WARNINGEWA13030

A hot radiator is under pressure. Therefore,do not remove the radiator cap when the en-gine is hot. Scalding hot fluid and steam maybe blown out, which could cause serious in-jury. When the engine has cooled, open theradiator cap as follows:Place a thick rag or a towel over the radiatorcap and slowly turn the radiator cap counter-clockwise toward the detent to allow any re-sidual pressure to escape. When the hissingsound has stopped, press down on the radi-ator cap and turn it counterclockwise to re-move.

1. Stand the vehicle upright on a level surface.2. Remove:

• Radiator cap “1”

3. Check:• Coolant level

Maximum level “a” or below Add coolantup to the maximum level.

NOTICEECA24260

• Adding water instead of coolant lowers theantifreeze content. If, therefore, water isused instead of coolant, check, and if nec-essary, adjust the antifreeze concentration.

• Use only distilled water. However, if dis-

tilled water is not available, soft water maybe used.

4. Start the engine, warm this up for severalminutes, and then stop it.


TIPBefore checking the coolant level, wait a fewminutes until the coolant has settled.

EAM30211

CHECKING THE COOLING SYSTEM1. Remove:

• Seat• Side cover (left/right)• Air scoop (left/right)

Refer to “GENERAL CHASSIS” on page 4-1.2. Check:

• Radiator• Radiator hoses

Crack/damage Replace.Refer to “RADIATOR” on page 6-2.

3. Install:• Air scoop (left/right)• Seat• Side cover (left/right)

Refer to “GENERAL CHASSIS” on page 4-1.

EAM30212

CHANGING THE COOLANT

WARNINGEWA13030


1. Place a container under the engine.2. Remove:

• Coolant drain bolt “1”

1. Radiator

ENGINE

3-12

3. Remove:• Radiator cap

Slowly loosen the radiator cap to drain cool-ant.

TIPWhen the radiator cap is loosened, coolant willgush out transversely; therefore, bring the con-tainer near to the outlet.

4. Thoroughly flush the cooling system withclean tap water.

5. Install:• Copper washer • Coolant drain bolt

6. Pour coolant.

WARNINGEWA13040

• If coolant splashes in your eyes, thorough-ly wash them with water and consult a doc-tor.

• If coolant splashes on your clothes, quicklywash it away with water and then with soapand water.

• If coolant is swallowed, induce vomitingand get immediate medical attention.

NOTICEECA13481

• Adding water instead of coolant lowers theantifreeze content of the coolant. If water isused instead of coolant, check, and if nec-essary, correct the antifreeze concentra-

tion of the coolant.• Use only distilled water. However, if dis-

tilled water is not available, soft water maybe used.

• If coolant comes into contact with paintedsurfaces, immediately wash them with wa-ter.

• Do not mix different types of antifreeze.

7. Install:• Radiator cap

8. Start the engine, warm this up for severalminutes, stop it, and then wait for it to cooldown.


Refer to “CHECKING THE COOLANT LEV-EL” on page 3-11.

Coolant drain bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)

Recommended coolantHigh quality ethylene glycol anti-freeze containing anti-cor-rosion for aluminum engine

Radiator (including all routes)0.90 L (0.95 US qt, 0.79 Imp.qt)

Coolant mixing ratio1:1 (Coolant:Water)

New

TR..

CHASSIS

3-13

EAM20136

CHASSISEAM30479

ADJUSTING THE FRONT DISC BRAKETIPThere should be no free play at the brake leverend.

1. Check:• Brake lever position “a”

2. Remove:• Brake lever cover

3. Adjust:• Brake lever position

a. Loosen the locknut “1”.b. Turn the adjusting bolt “2” until the speci-

fied brake lever position is obtained.

c. Tighten the locknut.

WARNINGEWA13050

A soft or spongy feeling in the brake levercan indicate the presence of air in the brakesystem. Before the vehicle is operated, the

air must be removed by bleeding the brakesystem. Air in the brake system will consid-erably reduce braking performance.

NOTICEECA13490

After adjusting the brake lever position,make sure there is no brake drag.

4. Install:• Brake lever cover

EAM30480

ADJUSTING THE REAR DISC BRAKE1. Check:

• Brake pedal position “a”Out of specification Adjust.

2. Adjust:• Brake pedal position

a. Loosen the locknut “1”.b. Turn the adjusting nut “2” until the speci-

fied brake pedal position is obtained.

WARNINGEWA20710

Adjust the pedal height between the maxi-mum “A” and the minimum “B” as shown. (Inthis adjustment, the bolt “3” end “a” shouldprotrude out of the lower adjusting nut “4”but not be less than 2.0 mm (0.08 in) “b”away from the brake pedal “5”).

Brake lever position100 mm (3.94 in)

Extent of adjustment86–105 mm (3.39–4.13 in)

Locknut (front brake lever posi-tion)

5 N·m (0.5 kgf·m, 3.7 lb·ft)

a

G088889

2

1T

R..

Brake pedal position (above the top of the footrest)

0.0 mm (0.00 in)

2

1

CHASSIS

3-14

c. Tighten the locknut to specification.

WARNINGEWA19150

A soft or spongy feeling in the brake pedalcan indicate the presence of air in the brakesystem. Before running, bleed the brake sys-tem. Air in the brake system will cause brak-ing performance to be reduced.

NOTICEECA13510

After adjusting the brake pedal position,make sure there is no brake drag.

EAM30234

CHECKING THE BRAKE FLUID LEVEL1. Stand the vehicle upright on a level surface.TIPIn order to ensure a correct reading of the brakefluid level, make sure that the top of the brakefluid reservoir is horizontal.

2. Check:• Brake fluid level

The minimum level mark “a” or below Add.

WARNINGEWA13090

• Use only the designated brake fluid. Otherbrake fluids may cause the rubber seals todeteriorate, causing leakage and poorbrake performance.

• Refill with the same type of brake fluid thatis already in the system. Mixing brake fluidsmay result in a harmful chemical reaction,leading to poor brake performance.

• When refilling, be careful that water doesnot enter the brake fluid reservoir. Waterwill significantly lower the boiling point ofthe brake fluid and could cause vapor lock.

NOTICEECA13540

Brake fluid may damage painted surfacesand plastic parts. Therefore, always clean upany spilt brake fluid immediately.

EAM30231

CHECKING THE FRONT BRAKE PADSThe following procedure applies to all of thebrake pads.1. Operate the brake.2. Check:

• Front brake padWear indicator grooves “1” almost touch thebrake disc Replace the brake pads as aset.Refer to “FRONT BRAKE” on page 4-11.

Rear brake pedal adjusting lock-nut

6 N·m (0.6 kgf·m, 4.4 lb·ft)

Specified brake fluidDOT 4

4

3

a b

3

5

A B

TR..

A. Front brakeB. Rear brake

CHASSIS

3-15

EAM30232

CHECKING THE REAR BRAKE PADSThe following procedure applies to all of thebrake pads.1. Operate the brake.2. Check:

• Rear brake padWear indicator grooves “1” almost disap-peared Replace the brake pads as a set.Refer to “REAR BRAKE” on page 4-22.

EAM30478

CHECKING THE FRONT BRAKE HOSE1. Check:

• Brake hoseCracks/damage/wear Replace.

2. Check:• Brake hose clamp

Loose connection Tighten the clamp bolt.3. Stand the vehicle upright and apply the front

brake several times.4. Check:

• Brake hoseBrake fluid leaks Replace the damagedbrake hose.Refer to “FRONT BRAKE” on page 4-11.

EAM30498

CHECKING THE REAR BRAKE HOSE1. Check:


2. Check:• Brake hose holder

Loose connection Tighten the holder bolt.3. Hold the vehicle upright and apply the rear

brake several times.4. Check:

• Brake hoseBrake fluid leakage Replace the damagedhose.Refer to “REAR BRAKE” on page 4-22.

EAM30499

CHECKING THE BRAKE OPERATION1. Check:

• Brake operationBrake not working properly Check thebrake system.Refer to “FRONT BRAKE” on page 4-11 and“REAR BRAKE” on page 4-22.

TIPDrive on the dry road, operate the front and rearbrakes separately and check to see if the brakesare operating properly.

EAM30477

BLEEDING THE HYDRAULIC BRAKE SYSTEM

WARNINGEWA19140

Bleed the brake system whenever:• The system is disassembled.• A brake hose is loosened, disconnected, or

replaced.• The brake fluid level is very low.• Brake operation is faulty.

1. Remove:• Brake master cylinder cap• Reservoir diaphragm• Reservoir float (front brake)• Protector (rear brake)

TIP• Be careful not to spill any brake fluid or allow

the reservoir to overflow.• Make sure that there is enough brake fluid be-

fore applying the brake. Ignoring this precau-tion could allow air to enter the brake system,considerably lengthening the bleeding proce-dure.

• If bleeding is difficult, it may be necessary to letthe brake fluid settle for a few hours. Repeatthe bleeding procedure when the tiny bubblesin the hose have disappeared.

2. Bleed the brake system.a. Fill the reservoir to the proper level with

the recommended brake fluid.

1

1

CHASSIS

3-16

b. Install the reservoir diaphragm.c. Connect the plastic hose “1” to the bleed

screw “2” securely, and place a containerunder the end of the plastic hose.

d. Slowly apply the brake several times.e. Fully pull the brake lever or fully press

down the brake pedal and hold it in posi-tion.

f. Loosen the bleed screw.TIPLoosening the bleed screw will release the pres-sure in the brake caliper and cause the brake le-ver to contact the throttle grip or the brake pedalto fully extend.

g. Tighten the bleed screw and then releasethe brake lever or brake pedal.

h. Repeat steps (d) to (g) until all of the airbubbles have disappeared from the brakefluid in the plastic hose.

TIPDuring the procedure, keep adding brake fluid tothe reservoir.

NOTICEECA24320

• Wipe off any brake fluid on the brake discs,tires, wheels, etc.

• Brake fluid may erode painted surfaces orplastic parts. Always clean up spilled fluid

immediately.

i. Tighten the bleed screw.

j. Pour brake fluid to the reservoir up to thespecified level.Refer to “CHECKING THE BRAKE FLUIDLEVEL” on page 3-14.

WARNINGEWA13110

After bleeding the hydraulic brake system,check the brake operation.

EAM30481

DRIVE CHAIN SLACK

NOTICEECA13550

A drive chain that is too tight will overloadthe engine and other vital parts, and one thatis too loose can skip and damage the swing-arm or cause an accident. Therefore, keepthe drive chain slack within the specified lim-its.

Checking the drive chain slack1. Use a maintenance stand to raise the rear

wheel off the ground.

WARNINGEWA13120

Securely support the vehicle so that there isno danger of it falling over.

2. Shift the transmission into the neutral posi-tion.

3. Pull the drive chain up above the drive chainguide installation bolt with a force of about 50N (5.0 kgf, 37 lbf).

4. Check:• Drive chain slack “a”

Out of specification Regulate.TIPMeasure drive chain slack between the drivechain guide and the bottom of the chain asshown.

A. FrontB. Rear

2 1

21

Brake caliper bleed screw6 N·m (0.6 kgf·m, 4.4 lb·ft)T

R..

CHASSIS

3-17

Adjusting the drive chain slack

WARNINGEWA13120


1. Adjust:• Drive chain slack

a. Loosen the wheel axle nut “1”.b. Loosen both locknuts “2”.c. Turn the adjusting bolt “3” until the speci-

fied drive chain slack is obtained.

TIP• To maintain the proper wheel alignment, adjust

both sides evenly.• Push the rear wheel forward to make sure that

there is no clearance between the swingarmend plates and the ends of the swingarm.

d. Tighten the wheel axle nut.

e. Tighten the drive chain puller locknut.

EAM30251

LUBRICATING THE DRIVE CHAINThe drive chain consists of many interactingparts. If the drive chain is not maintained proper-ly, it will wear out quickly. Therefore, the drivechain should be serviced, especially when thevehicle is used in dusty areas.This vehicle has a drive chain with small rubberO-rings between each side plate. Steam clean-ing, high-pressure washing, certain solvents,and the use of a coarse brush can damagethese O-rings. Therefore, use only kerosene toclean the drive chain. Wipe the drive chain dryand thoroughly lubricate it with engine oil orchain lubricant that is suitable for O-ring chains.Do not use any other lubricants on the drivechain since they may contain solvents that coulddamage the O-rings.

EAM30247

CHECKING AND ADJUSTING THE STEERING HEAD1. Use a maintenance stand to raise the front


WARNINGEWA13120


2. Check:• Steering head

Grasp the bottom of the front fork legs andgently rock the front fork.Blinding/looseness Adjust the steeringhead.

3. Remove:• Handlebar

Refer to “HANDLEBAR” on page 4-32.• Upper bracket

Refer to “STEERING HEAD” on page 4-50.4. Adjust:

• Steering heada. Remove the washer “1”.

Drive chain slack (Maintenance stand)

48.0–58.0 mm (1.89–2.28 in)

Rear wheel axle nut125 N·m (12.5 kgf·m, 92 lb·ft)

Drive chain puller locknut19 N·m (1.9 kgf·m, 14 lb·ft)

2

1 3

TR..

TR..

Recommended lubricantChain lubricant suitable for O-ring chains

CHASSIS

3-18

b. After loosening the ring nut “2” with asteering nut wrench “3”, tighten it to thespecified torque.

TIP• Set the torque wrench at a right angle to the

steering nut wrench.• Move the steering to the left and right a couple

of times to check that it moves smoothly.

c. Turn the front fork to the right and left a fewtimes, and make sure that the steering ro-tates smoothly. If it does not turn smooth-ly, remove the lower bracket and checkthe upper and lower bearings.Refer to “STEERING HEAD” on page4-50.

d. Loosen the ring nut fully turn and thentighten it to specification with a steeringnut wrench.

WARNINGEWA21110

Do not overtighten the steering ring nut.

e. Check the steering head for looseness orbinding by turning the front fork all the wayin both directions. If any binding is felt, re-move the lower bracket and check the up-per and lower bearings.Refer to “STEERING HEAD” on page4-50.

f. Install the washer “1”.

5. Install:• Upper bracket

Refer to “STEERING HEAD” on page 4-50.• Handlebar

Refer to “HANDLEBAR” on page 4-32.

EAM30502

LUBRICATING THE STEERING HEAD1. Lubricate:

• Upper bearing• Lower bearing• Bearing race

EAM30338

CHECKING THE FRONT FORK LEGS1. Stand the vehicle upright on a level surface.

WARNINGEWA13120


2. Check:• Inner tube

Damage/scratches Replace.• Front fork leg

Oil leaks between inner tube and outer tube Replace the oil seal.

3. Hold the vehicle upright and apply the frontbrake.

Steering nut wrench90890-01403

Exhaust flange nut wrenchYU-A9472

Steering ring nut (initial tighten-ing torque)

38 N·m (3.8 kgf·m, 28 lb·ft)

1

3

2

TR..

Steering ring nut (final tightening torque)

7 N·m (0.7 kgf·m, 5.2 lb·ft)

Recommended lubricantLithium-soap-based grease

TR..

1

CHASSIS

3-19

4. Check:• Front fork operation

Push down hard on the handlebar severaltimes and check if the front fork reboundssmoothly.Unsmooth operation Correct or replace.Refer to “FRONT FORK” on page 4-38.

5. Check:• Protector guide “1”

Out of specification Replace.TIPThe protector guide reaches the limit of its usewhen it is worn down to the same height “a” asof the outer tube circumference.

6. Remove:• Protector• Dust seal “1”

NOTICEECA24330

Be careful not to damage the dust seal andthe inner tube by a driver.

7. Clean:• Dust seal “a”• Oil seal “b”

TIP• Clean the dust seal and oil seal after every run.• Apply lithium-soap-based grease on the inner

tube.

EAM30239

ADJUSTING THE FRONT FORK LEGS

WARNINGEWA19180

• Always adjust the left and right front forksevenly. If this is not done, the vehicle mayhave poor stability.

• Securely support the vehicle so that thereis no danger of it falling over.

Rebound damping

NOTICEECA24340

Do not turn the adjuster forcibly beyond itsadjusting range.

1. Adjust:• Rebound damping

a. Turn the adjuster “1” in the direction of “a”or “b” to make an adjustment.

TIPAlthough the total number of clicks of a dampingforce adjusting mechanism may not exactlymatch the above specifications due to small dif-ferences in production, the actual number ofclicks always represents the entire adjustingrange. To obtain a precise adjustment, it would

1

a

1

Direction “a”Rebound damping is increased (sus-pension is harder).

Direction “b”Rebound damping is decreased (sus-pension is softer).

Rebound dampingMinimum (soft)

20 click(s) in direction “b”*Standard

11 click(s) in direction “b”*Maximum (hard)

0 click(s) in direction “b”**With the adjusting screw fully turned in di-rection “a”

LS

a

b

CHASSIS

3-20

be advisable to check the number of clicks ofeach damping force adjusting mechanism andto modify the specifications as necessary.

Compression damping

NOTICEECA24350


1. Adjust:• Compression damping


TIPAlthough the total number of clicks of a dampingforce adjusting mechanism may not exactlymatch the above specifications due to small dif-ferences in production, the actual number ofclicks always represents the entire adjustingrange. To obtain a precise adjustment, it wouldbe advisable to check the number of clicks ofeach damping force adjusting mechanism andto modify the specifications as necessary.

Air bleeding from front forkTIPIf the front fork initial movement feels stiff duringa run, relieve the front fork internal pressure.

1. Use a maintenance stand to raise the frontwheel off the ground.

WARNINGEWA13120


2. Remove the bleed screw “1” and release theinternal pressure from the front fork.

3. Tighten:• Bleed screw

EAM30482

CHECKING THE REAR SHOCK ABSORBER ASSEMBLY1. Stand the vehicle upright on a level surface.

WARNINGEWA13120


2. Check:• Rear shock absorber assembly

Gas leaks/oil leaks Replace the rear shockabsorber assembly.Refer to “REAR SHOCK ABSORBER AS-SEMBLY” on page 4-54.

Direction “a”Compression damping is increased (suspension is harder).

Direction “b”Compression damping is decreased (suspension is softer).

Compression dampingMinimum (soft)


15 click(s) in direction“b”*Maximum (hard)


Bleed screw (front fork)1.3 N·m (0.13 kgf·m, 0.95 lb·ft)T

R..

CHASSIS

3-21

3. Check:• Rear shock absorber assembly smooth ac-

tion• Rear suspension link smooth action

Sit astride the seat and shake your body upand down several times to check whether therear shock absorber assembly operatessmoothly.Unsmooth operation Correct or replace.Refer to “REAR SHOCK ABSORBER AS-SEMBLY” on page 4-54.

EAM30242

ADJUSTING THE REAR SHOCK ABSORBER ASSEMBLYUse a maintenance stand to raise the rear wheeloff the ground.

WARNINGEWA13120


Spring preload

NOTICEECA24360


1. Remove:• Rear frame

Refer to “REAR SHOCK ABSORBER AS-SEMBLY” on page 4-54.

2. Adjust:• Spring preload

a. Loosen the locknut “1”.b. Loosen the adjuster “2” until there is some

clearance between the spring and the ad-juster.

c. Measure the spring free length “a”.

d. Turn the adjuster in the direction of “b” or“c” to make an adjustment.

TIP• Be sure to remove all dirt and mud from around

the locknut and adjusting ring before adjust-ment.

• The length of the spring (installed) changes 1.5mm (0.06 in) per turn of the adjusting ring.

e. Tighten the locknut.3. Install:

• Rear frameRefer to “REAR SHOCK ABSORBER AS-SEMBLY” on page 4-54.

Rebound damping

NOTICEECA24370


1. Adjust:• Rebound damping


Direction “b”Spring preload is increased (suspen-sion is harder).

Direction “c”Spring preload is decreased (suspen-sion is softer).

Spring preload adjusting positionsMinimum

Position in which the spring is turned in 1.5 mm (0.06 in) from its free length.

StandardPosition in which the spring is turned in 6.0 mm (0.24 in) from its free length.

MaximumPosition in which the spring is turned in 18.0 mm (0.71 in) from its free length.

bb cc

CHASSIS

3-22


Compression damping (for fast compres-sion damping)

NOTICEECA24370


1. Adjust:• Compression damping (for fast compression

damping)a. Turn the adjuster “1” in the direction of “a”

or “b” to make an adjustment.

TIPTo obtain a precise adjustment, it is advisable tocheck the actual total number of turns of thedamping force adjusting mechanism. This ad-justment range may not exactly match the spec-ifications listed due to small differences inproduction.

Compression damping (for slow compres-sion damping)

NOTICEECA24390


1. Adjust:• Compression damping (for slow compression

damping)a. Turn the adjuster “1” in the direction of “a”

or “b” to make an adjustment.

Direction “a”Rebound damping is increased (sus-pension is harder).

Direction “b”Rebound damping is decreased (sus-pension is softer).

Rebound dampingMinimum (soft)






Fast compression dampingMinimum (soft)

2 turn(s) in direction “b”*Standard

1-5/8 turn(s) in direction “b”*Maximum (hard)

0 turn(s) in direction “b”**With the adjusting screw fully turned in di-rection “a”



CHASSIS

3-23


EAM30240

CHECKING THE SWINGARM OPERATION1. Check:

• Swingarm smooth action• Swingarm free play

Refer to “SWINGARM” on page 4-59.

EAM30500

LUBRICATING THE SWINGARM PIVOT1. Lubricate:

• Oil seals• Collars

Refer to “INSTALLING THE SWINGARM” onpage 4-60.

EAM30501

CHECKING THE CONNECTING ARM AND RELAY ARMRefer to “CHECKING THE CONNECTING ARMAND RELAY ARM” on page 4-56.

EAM30243

CHECKING THE TIRES1. Measure:

• Tire pressureOut of specification Regulate.

TIP• Check the tire while it is cold.• Because if the bead stopper tightening nut is

loose when the tire pressure is low, the tirecould slip off the rim, thus be sure to check andtighten the bead stopper tightening nut “a”.

• If the tire valve stem “b” is found tilted, the tireis considered to be slipping off its position. Cor-rect the tire position.

EAM30244

CHECKING AND TIGHTENING THE SPOKES1. Check:

• SpokeBend/damage Replace.Loose Tighten.

TIPA tight spoke will emit a clear, ringing tone; a

Slow compression dampingMinimum (soft)





Tire air pressure (measured on cold tires)

Front100 kPa (1.00 kgf/cm², 15 psi)

Rear100 kPa (1.00 kgf/cm², 15 psi)

a. Bead stopper tightening nutb. Tire valve stem

a

b

G089059

CHASSIS

3-24

loose spoke will sound flat.

2. Tighten:• Spoke

(with a spoke nipple wrench “1”)

TIP• Do not give a half turn (180) or more for one

tightening.• Make sure that tightening after a break-in is

done until the initial looseness in nipples disap-pears.

• Make sure that tightening is done in stages, notat a time.

EAM30245

CHECKING THE WHEELS1. Check:

• WheelDamage/out-of-round Replace.

WARNINGEWA13260

Never attempt to make any repairs to thewheel.

TIPAfter replacing a tire or a wheel, always balancethe wheel.

EAM30246

CHECKING THE WHEEL BEARINGS1. Check:

• Wheel bearingRefer to “CHECKING THE FRONT WHEEL”on page 4-4 and “CHECKING THE REARWHEEL” on page 4-8.

EAM30253

CHECKING THE CHASSIS FASTENERSMake sure that all nuts, bolts, and screws areproperly tightened.Refer to “CHASSIS TIGHTENING TORQUES”on page 2-11.

EAM30248

CHECKING AND LUBRICATING THE CABLESThe following procedure applies to all of the in-ner and outer cables.

WARNINGEWA13270

Damaged outer cable may cause the cable tocorrode and interfere with its movement. Re-place damaged outer cable and inner cablesas soon as possible.

1. Check:• Outer cable

Damage Replace.2. Check:

• Cable operationRough movement Lubricate.

TIPHold the cable end upright and pour a few dropsof lubricant into the cable sheath or use a suit-able lubricating device.

EAM30483

LUBRICATING THE BRAKE LEVER1. Lubricate the pivoting points and metal-to-

metal moving parts of the following parts.• Brake lever

EAM30503

LUBRICATING THE CLUTCH LEVER1. Lubricate the pivoting points and metal-to-

metal moving parts of the following parts.• Clutch lever

EAM30250

LUBRICATING THE PEDAL1. Lubricate the pivoting point and metal-to-met-

al moving parts of the pedal.

Spoke nipple wrench (6–7)90890-01521

Spoke nipple wrench (6–7)YM-01521

Nipple (spoke)2.5 N·m (0.25 kgf·m, 1.8 lb·ft)

1

G089060

TR..

Recommended lubricantEngine oil or a suitable cable lu-bricant

Recommended lubricantSilicone grease


CHASSIS

3-25

EAM30504

CHECKING THE SIDESTAND1. Check:

• Sidestand operationCheck that the sidestand moves smoothly.Rough movement Repair or replace.

EAM30252

LUBRICATING THE SIDESTANDLubricate the pivoting point and metal-to-metalmoving parts of the sidestand.



ELECTRICAL SYSTEM

3-26

EAM20137

ELECTRICAL SYSTEMEAM30255

CHECKING THE IGNITION TIMING1. Remove:

• Fuel tankRefer to “FUEL TANK” on page 7-1.• Spark plug• Crankcase cover (left)

2. Attach:• Dial gauge “1”• Spark plug hole dial stand “2”

3. Rotate the magneto rotor “1” until the pistonreaches top dead center (TDC). When thishappens, the needle on the dial gauge willstop and reverse directions even though therotor is being turned in the same direction.

4. Set the dial gauge to zero at TDC.5. From TDC, rotate the rotor clockwise until the

dial gauge indicates that the piston is at aspecified distance from TDC.

6. Check:• Ignition timing

Punch mark “a” on rotor should be alignedwith punch mark “b” on stator.Not aligned Adjust.

7. Adjust:• Ignition timing

a. Loosen the stator coil screws “1”.b. Align the punch mark on the rotor with

punch mark on the stator by moving thestator “2”.

c. Tighten the stator coil screws.

Dial gauge & stand set90890-01252

Dial gauge setYU-03097-B

Ignition timing (B.T.D.C.)0.50 mm (0.02 in)

Stator coil screw7 N·m (0.7 kgf·m, 5.2 lb·ft)T

R..

1

2

3

4

5

6

7

8

9

10

CHASSIS

GENERAL CHASSIS........................................................................................4-1REMOVING THE NUMBER PLATE ...........................................................4-2REMOVING THE SIDE COVER.................................................................4-2

FRONT WHEEL ................................................................................................4-3REMOVING THE FRONT WHEEL.............................................................4-4DISASSEMBLING THE FRONT WHEEL ...................................................4-4CHECKING THE FRONT WHEEL .............................................................4-4ASSEMBLING THE FRONT WHEEL .........................................................4-5INSTALLING THE FRONT WHEEL ...........................................................4-5

REAR WHEEL ..................................................................................................4-7REMOVING THE REAR WHEEL ...............................................................4-8DISASSEMBLING THE REAR WHEEL .....................................................4-8CHECKING THE REAR WHEEL................................................................4-8CHECKING AND REPLACING THE REAR WHEEL SPROCKET.............4-8ASSEMBLING THE REAR WHEEL ...........................................................4-9INSTALLING THE REAR WHEEL..............................................................4-9

FRONT BRAKE ..............................................................................................4-11INTRODUCTION ......................................................................................4-15CHECKING THE FRONT BRAKE DISC ..................................................4-15REPLACING THE FRONT BRAKE PADS ...............................................4-15REMOVING THE FRONT BRAKE CALIPER ...........................................4-17DISASSEMBLING THE FRONT BRAKE CALIPER .................................4-17CHECKING THE FRONT BRAKE CALIPER............................................4-17ASSEMBLING THE FRONT BRAKE CALIPER .......................................4-18INSTALLING THE FRONT BRAKE CALIPER..........................................4-18REMOVING THE FRONT BRAKE MASTER CYLINDER ........................4-19CHECKING THE FRONT BRAKE MASTER CYLINDER.........................4-19ASSEMBLING THE FRONT BRAKE MASTER CYLINDER.....................4-19INSTALLING THE FRONT BRAKE MASTER CYLINDER.......................4-20

REAR BRAKE ................................................................................................4-22INTRODUCTION ......................................................................................4-26CHECKING THE REAR BRAKE DISC.....................................................4-26REPLACING THE REAR BRAKE PADS..................................................4-26REMOVING THE REAR BRAKE CALIPER .............................................4-28DISASSEMBLING THE REAR BRAKE CALIPER....................................4-28CHECKING THE REAR BRAKE CALIPER ..............................................4-28ASSEMBLING THE REAR BRAKE CALIPER..........................................4-28INSTALLING THE REAR BRAKE CALIPER ............................................4-29REMOVING THE REAR BRAKE MASTER CYLINDER...........................4-29CHECKING THE REAR BRAKE MASTER CYLINDER ...........................4-30ASSEMBLING THE REAR BRAKE MASTER CYLINDER.......................4-30INSTALLING THE REAR BRAKE MASTER CYLINDER .........................4-31

HANDLEBAR..................................................................................................4-32REMOVING THE HANDLEBAR ...............................................................4-33CHECKING THE HANDLEBAR................................................................4-33INSTALLING THE HANDLEBAR..............................................................4-33

FRONT FORK .................................................................................................4-38REMOVING THE FRONT FORK LEGS ...................................................4-40DISASSEMBLING THE FRONT FORK LEGS .........................................4-40CHECKING THE FRONT FORK LEGS....................................................4-41ASSEMBLING THE FRONT FORK LEGS ...............................................4-42INSTALLING THE FRONT FORK LEGS..................................................4-48

STEERING HEAD...........................................................................................4-50REMOVING THE LOWER BRACKET......................................................4-51CHECKING THE STEERING HEAD ........................................................4-51INSTALLING THE STEERING HEAD ......................................................4-51

REAR SHOCK ABSORBER ASSEMBLY ......................................................4-54HANDLING THE REAR SHOCK ABSORBER .........................................4-56DISPOSING OF A REAR SHOCK ABSORBER.......................................4-56REMOVING THE REAR SHOCK ABSORBER ASSEMBLY....................4-56CHECKING THE REAR SHOCK ABSORBER ASSEMBLY.....................4-56CHECKING THE CONNECTING ARM AND RELAY ARM ......................4-56INSTALLING THE RELAY ARM...............................................................4-57INSTALLING THE REAR SHOCK ABSORBER ASSEMBLY...................4-57

SWINGARM ....................................................................................................4-59REMOVING THE SWINGARM.................................................................4-60CHECKING THE SWINGARM .................................................................4-60INSTALLING THE SWINGARM ...............................................................4-60

CHAIN DRIVE .................................................................................................4-62REMOVING THE DRIVE CHAIN..............................................................4-63CHECKING THE DRIVE CHAIN ..............................................................4-63CHECKING THE DRIVE SPROCKET......................................................4-64CHECKING THE REAR WHEEL SPROCKET .........................................4-64INSTALLING THE DRIVE CHAIN ............................................................4-64

GENERAL CHASSIS

4-1

EAM20094

GENERAL CHASSISRemoving the seat and side cover

Order Job/Parts to remove Q’ty Remarks

1 Seat 12 Air scoop (left and right) 2

3 Side cover (left) 1

4 Side cover (right) 15 Number plate 1

1

5

2

4

3

2

19 N・m (1.9 kgf・m, 14 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

6 N・m (0.6 kgf・m, 4.4 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

6 N・m (0.6 kgf・m, 4.4 lb・ft)

19 N・m (1.9 kgf・m, 14 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

GENERAL CHASSIS

4-2

EAM30371

REMOVING THE NUMBER PLATE1. Remove:

• Number plate bolt• Number plate “1”

TIP• The projection “a” is inserted into the band of

the number plate. Pull the band off the projec-tion before removal.

• Remove the clutch cable “2” from the cableguide “b” on the number plate.

• The projection “c” on the lower bracket is in-serted into the number plate. Remove thenumber plate by pulling it off the projection.

• When installing the number plate, insert theprojection on the number plate into the hole inthe upper side of the band.

EAM30459

REMOVING THE SIDE COVER1. Remove:

• Side cover bolt• Side cover (left and right) “1”

TIPDraw the side cover backward to remove it be-cause its claws “a” are inserted in the air filtercase.

FRONT WHEEL

4-3

EAM20095

FRONT WHEELRemoving the front wheel


Use a maintenance stand to raise the front wheel off the ground.

1 Front wheel axle pinch bolt 4 Loosen.

2 Front wheel axle nut 1

3 Front wheel axle 14 Front wheel 1

5 Collar 2

6 Oil seal 27 Bearing 2

8 Brake disc 1

12 N・m (1.2 kgf・m, 8.9 lb・ft)

12

3

4

56

7

8

21 N・m (2.1 kgf・m, 15 lb・ft)

105 N・m (10.5 kgf・m, 77 lb・ft)

21 N・m (2.1 kgf・m, 15 lb・ft)

5 6

7

1

FRONT WHEEL

4-4

EAM30017

REMOVING THE FRONT WHEEL1. Use a maintenance stand to raise the front


WARNINGEWA13120


2. Remove:• Front wheel

EAM30019

DISASSEMBLING THE FRONT WHEEL1. Remove:

• Oil seal• Bearing

a. Clean the outside of the front wheel hub.b. Remove the oil seals “1” with a flat-head

screwdriver.TIPTo prevent damaging the wheel, place a rag “2”between the screwdriver and the wheel surface.

c. Remove the bearings with a bearing pull-er.

EAM30018

CHECKING THE FRONT WHEEL1. Check:

• Front wheel axleRoll the front wheel axle on a flat surface.Bends Replace.

WARNINGEWA13460

Do not attempt to straighten a bent wheel ax-le.

2. Check:• Tire• Front wheel

Damage/wear Replace.Refer to “CHECKING THE TIRES” on page3-23 and “CHECKING THE WHEELS” onpage 3-24.

3. Check:• Spoke

Bend/damage Replace.Loose Tighten.Tap the spokes with a screwdriver.

TIPA tight spoke will emit a clear, ringing tone; aloose spoke will sound flat.

4. Tighten:• Spoke

Refer to “CHECKING AND TIGHTENINGTHE SPOKES” on page 3-23.

TIPAfter tightening the spokes, measure the wheelrunout.

5. Measure:• Radial wheel runout “1”• Lateral wheel runout “2”

Out of specification Repair/replace.

6. Check:• Collar

Damage/wear Replace.7. Check:

• BearingFront wheel turns roughly or is loose Re-

1

2

G088896

Nipple (spoke)2.5 N·m (0.25 kgf·m, 1.8 lb·ft)

Radial wheel runout limit2.0 mm (0.08 in)

Lateral wheel runout limit2.0 mm (0.08 in)

TR..

11

2

G088897

FRONT WHEEL

4-5

place the wheel bearings.• Oil seal

Damage/wear Replace.

EAM30020

ASSEMBLING THE FRONT WHEEL1. Install:

• Bearing (left side) “1”• Spacer “2”• Bearing (right side) “3”• Oil seal “4”

TIP• Apply the lithium-soap-based grease to the

bearing and the oil seal lip when installing.• Left side of bearing shall be installed first.• Install the oil seal with its manufacture’s marks

or numbers facing outward.

NOTICEECA24420

Install the bearing by pressing its outer raceparallel.

NOTICEECA18110

Do not contact the wheel bearing inner race“1” or balls “2”. Contact should be madeonly with the outer race “3”.

TIPUse a socket “4” that matches the diameter ofthe bearing outer race and that of the oil seal.

2. Install:• Brake disc• Brake disc bolt

TIPTighten the bolts in stages and in a crisscrosspattern.

3. Install:• Collar “1”

TIP• Apply the lithium-soap-based grease on the oil

seal lip.• Install the collars with their projections “a” fac-

ing the wheel.

EAM30021

INSTALLING THE FRONT WHEEL1. Install:

• Front wheelTIPInstall the brake disc “1” between the brake pads“2” correctly.

New

LS

LS

32

4

41

Front brake disc bolt12 N·m (1.2 kgf·m, 8.9 lb·ft)LOCTITE®

G088898

TR..

a

1

a

FRONT WHEEL

4-6

2. Install:• Front wheel axle “1”

TIPApply the lithium-soap-based grease to the frontwheel axle.

3. Tighten:• Front wheel axle nut “1”

NOTICEECA24430

Before tightening the front wheel axle nut,push down hard on the handlebar(s) severaltimes and check if the front fork reboundssmoothly.

4. Tighten:• Front wheel axle pinch bolt “1”

Front wheel axle nut105 N·m (10.5 kgf·m, 77 lb·ft)

Front wheel axle pinch bolt21 N·m (2.1 kgf·m, 15 lb·ft)

1

TR..

TR..

REAR WHEEL

4-7

EAM20096

REAR WHEELRemoving the rear wheel


Use a maintenance stand to raise the rear wheel off the ground.

1 Rear wheel axle nut 1

2 Rear wheel axle 1

3 Drive chain puller 24 Rear wheel 1

5 Collar 2

6 Rear wheel sprocket 17 Oil seal 2

8 Circlip 1

9 Bearing 210 Brake disc 1

19 N・m (1.9 kgf・m, 14 lb・ft)

42 N・m (4.2 kgf・m, 31 lb・ft)

125 N・m (12.5 kgf・m, 92 lb・ft) 12 N・m (1.2 kgf・m, 8.9 lb・ft)

19 N・m (1.9 kgf・m, 14 lb・ft)

1

2

3

4

5

6

78

9

10

53

79

REAR WHEEL

4-8

EAM30022

REMOVING THE REAR WHEEL1. Use a maintenance stand to raise the rear


WARNINGEWA13120


2. Remove:• Rear wheel axle nut “1”

3. Loosen:• Locknut “2”

4. Tighten:• Adjusting bolt “3”

5. Remove:• Rear wheel axle• Rear wheel

TIP• Push the rear wheel forward and remove the

drive chain from the rear wheel sprocket.• Do not depress the brake pedal with the rear

wheel removed.

EAM30024

DISASSEMBLING THE REAR WHEEL1. Remove:

• Oil seal• Bearing

Refer to “DISASSEMBLING THE FRONTWHEEL” on page 4-4.

EAM30023

CHECKING THE REAR WHEEL1. Check:

• Rear wheel axle• Rear wheel• Bearing• Oil seal

Refer to “CHECKING THE FRONT WHEEL”on page 4-4.

2. Check:• Tire• Rear wheel

Damage/wear Replace.

Refer to “CHECKING THE TIRES” on page3-23 and “CHECKING THE WHEELS” onpage 3-24.

3. Check:• Spoke


4. Measure:• Radial wheel runout• Lateral wheel runout


EAM30025

CHECKING AND REPLACING THE REAR WHEEL SPROCKET1. Check:

• Rear wheel sprocketMore than 1/4 tooth wear “a” Replace therear wheel sprocket and the drive sprocket asa set.Bent tooth Replace the rear wheel sprock-et and the drive sprocket as a set.

2. Replace:• Rear wheel sprocket

a. Remove the self-locking nuts and the rearwheel sprocket.

b. Clean the rear wheel drive hub with aclean cloth, especially the surfaces thatcontact the sprocket.

c. Install the new rear wheel sprocket.

1

2

3

Radial wheel runout limit2.0 mm (0.08 in)

Lateral wheel runout limit2.0 mm (0.08 in)

b. Correct

1. Drive chain roller2. Rear wheel sprocket

Rear wheel sprocket nut42 N·m (4.2 kgf·m, 31 lb·ft)

G088904

TR..

REAR WHEEL

4-9

TIPTighten the self-locking nuts in stages and in acrisscross pattern.

EAM30026

ASSEMBLING THE REAR WHEEL1. Install:

• Bearing (right side) “1”• Circlip “2” • Spacer “3”• Bearing (left side) “4”• Oil seal “5”

TIP• Apply the lithium-soap-based grease to the

bearing and the oil seal lip when installing.• Install the bearing with seal facing outward.• Right side of bearing shall be installed first.• Install the oil seal with its manufacture’s marks


NOTICEECA24440

Install the bearing by pressing its outer raceparallel.

NOTICEECA18110

Do not contact the wheel bearing inner race“1” or balls “2”. Contact should be madeonly with the outer race “3”.

TIPUse a socket “4” that matches the diameter ofthe bearing outer race and that of the oil seal.

2. Install:• Brake disc• Brake disc bolt

TIPTighten the bolts in stages and in a crisscrosspattern.


TIPApply the lithium-soap-based grease on the oilseal lip.

EAM30027

INSTALLING THE REAR WHEEL1. Install:

• Rear wheelTIPInstall the brake disc “1” between the brake pads“2” correctly.

New

New

1

2

43

5

5

Rear brake disc bolt12 N·m (1.2 kgf·m, 8.9 lb·ft)LOCTITE®

G088898

TR..

1

REAR WHEEL

4-10

2. Install:• Drive chain “1”

TIPPush the rear wheel “2” forward and install thedrive chain.

3. Install:• Left drive chain puller “1”• Rear wheel axle “2”

TIP• Install the left drive chain puller, and insert the

rear wheel axle from the left side.• Apply the lithium-soap-based grease to the

rear wheel axle.

4. Install:• Right drive chain puller “1”• Washer “2”• Rear wheel axle nut “3”

TIPTemporarily tighten the rear wheel axle nut atthis point.

5. Adjust:• Drive chain slack “a”

Refer to “DRIVE CHAIN SLACK” on page3-16.

6. Tighten:• Rear wheel axle nut “1”

• Locknut “2”

12


48.0–58.0 mm (1.89–2.28 in)

Rear wheel axle nut125 N·m (12.5 kgf·m, 92 lb·ft)

Drive chain puller locknut19 N·m (1.9 kgf·m, 14 lb·ft)

1

2

3

TR..

TR..

12

FRONT BRAKE

4-11

EAM20097

FRONT BRAKERemoving the front brake caliper


Brake fluidDrain.Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM” on page 3-15.

1 Union bolt 1

2 Copper washer 2

3 Front brake hose 14 Brake pad pin plug 1

5 Brake pad pin 1

6 Brake pad 27 Brake pad spring 1

8 Front brake caliper assembly 1

9 Front brake caliper bracket 1

39

1

28

457

6

28 N・m (2.8 kgf・m, 21 lb・ft)

30 N・m (3.0 kgf・m, 22 lb・ft)

2.5 N・m (0.25 kgf・m, 1.8 lb・ft)

17 N・m (1.7 kgf・m, 13 lb・ft)

6 N・m (0.6 kgf・m, 4.4 lb・ft)

FRONT BRAKE

4-12

Disassembling the front brake caliper


1 Brake caliper piston 2

2 Brake caliper piston dust seal 2

3 Brake caliper piston seal 24 Bleed screw 1

1 2

3

4

.

6 N・m (0.6 kgf・m, 4.4 lb・ft)

FRONT BRAKE

4-13

Removing the front brake master cylinder



1 Brake lever 1

2 Union bolt 13 Copper washer 2

4 Front brake hose 1

5 Brake master cylinder reservoir cap 16 Brake master cylinder reservoir diaphragm 1

7 Front brake master cylinder float 1

8 Front brake master cylinder holder 19 Front brake master cylinder 1

5

6

7

2

3

4

8

91

30 N・m (3.0 kgf・m, 22 lb・ft)

6 N・m (0.6 kgf・m, 4.4 lb・ft)

6 N・m (0.6 kgf・m, 4.4 lb・ft)

1.5 N・m (0.15 kgf・m, 1.1 lb・ft)

9 N・m (0.9 kgf・m, 6.6 lb・ft)

FRONT BRAKE

4-14

Disassembling the front brake master cylinder


1 Push rod 1

2 Dust boot 1

3 Circlip 14 Washer 1

5 Brake master cylinder kit 1

5

4

32

1

New

New

FRONT BRAKE

4-15

EAM30028

INTRODUCTION

WARNINGEWA19210

If you need to disassemble the disc brakecomponents, observe the following precau-tions.• Never disassemble the brake components

unless absolutely necessary.• If there is any problem with connections on

the hydraulic brake system, perform thefollowing jobs. Disassemble the brake sys-tem, drain the brake fluid, and clean it. Afterthat, add a suitable amount of brake fluid.Then, bleed it after reassembly.

• Use only brake fluid for washing brakecomponents.

• Use new brake fluid for cleaning the brakecomponents.

• Immediately wipe off the spilled brake fluidto avoid damage to painted surfaces orplastic parts.

• Handle brake fluid with special care not tolet it enter your eyes so that you may notlost your eyesight.

• FIRST AID FOR BRAKE FLUID ENTERINGTHE EYES:

• Flush with water for 15 minutes and get im-mediate medical attention.

EAM30029

CHECKING THE FRONT BRAKE DISC1. Check:

• Front brake discDamage/galling Replace.

2. Measure:• Brake disc thickness

Measure the brake disc thickness at a few dif-ferent locations.Out of specification Replace.

3. Measure:• Brake disc runout

Out of specification Correct the brake discrunout or replace the brake disc.

a. Place the vehicle on a maintenance standso that the front wheel is elevated.

b. Remove the brake caliper.c. Hold the dial gauge at a right angle against

the brake disc surface.d. Measure the runout 1.5 mm (0.06 in)

above the brake disc edge.

4. Adjust:• Brake disc runout

a. Remove the front wheel.Refer to “FRONT WHEEL” on page 4-3.

b. Remove the brake disc.c. Rotate the brake disc by one bolt hole.d. Install the brake disc.

TIPTighten the brake disc bolts in stages and in acrisscross pattern.

e. Measure the brake disc runout.f. If out of specification, repeat the adjust-

ment steps until the brake disc runout iswithin specification.

g. If the brake disc runout cannot be broughtwithin specification, replace the brakedisc.

h. Install the front wheel.Refer to “FRONT WHEEL” on page 4-3.

EAM30519

REPLACING THE FRONT BRAKE PADSTIPWhen replacing the brake pads, it is not neces-sary to disconnect the brake hose or disassem-ble the brake caliper.

1. Remove:• Brake pad

a. Remove the pad pin plug “1”.

Brake disc thickness limit2.5 mm (0.10 in)

Brake disc runout limit (as mea-sured on wheel)

0.15 mm (0.0059 in)

Front brake disc bolt12 N·m (1.2 kgf·m, 8.9 lb·ft)LOCTITE®

G098641

TR..

FRONT BRAKE

4-16

b. Loosen the pad pin “2”.c. Remove the brake caliper “3” from the

front fork.

d. Remove the pad pin and brake pads “4”.

2. Measure:• Brake pad wear limit “a”

Out of specification Replace the brakepads as a set.

3. Install:• Brake pad

a. Connect the plastic hose “1” to the bleedscrew “2” and place a container under theend of the plastic hose.

b. Loosen the bleed screw and push thebrake caliper piston in.

WARNINGEWA19160

Do not reuse the drained brake fluid.

c. Tighten the bleed screw.

d. Install the brake pads “3” and the pad pin.TIP• Install the brake pads with their projections “a”

into the brake caliper recesses “b”.• Temporarily tighten the pad pin at this point.

e. Install the brake caliper “4” and tighten thepad pin “5”.

Brake pad lining thickness limit1.0 mm (0.04 in)

4

a

Brake caliper bleed screw6 N·m (0.6 kgf·m, 4.4 lb·ft)

Front brake caliper bolt28 N·m (2.8 kgf·m, 21 lb·ft)

Brake pad pin17 N·m (1.7 kgf·m, 13 lb·ft)

2

1

TR..

3

ab

TR..

FRONT BRAKE

4-17

f. Install the pad pin plug “6”.


Refer to “CHECKING THE BRAKE FLUIDLEVEL” on page 3-14.

5. Check:• Brake lever operation

A softy or spongy feeling Bleed the brakesystem.Refer to “BLEEDING THE HYDRAULICBRAKE SYSTEM” on page 3-15.

EAM30030

REMOVING THE FRONT BRAKE CALIPERTIPBefore disassembling the brake caliper, drainthe brake fluid from the entire brake system.

1. Remove:• Union bolt• Copper washer• Brake hose

TIPPut the end of the brake hose into a containerand pump out the brake fluid.

EAM30031

DISASSEMBLING THE FRONT BRAKE CALIPER1. Remove:

• Brake caliper piston “1”• Brake caliper piston dust seal “2”• Brake caliper piston seal “3”

a. Blow compressed air into the brake hosejoint opening to force out the piston fromthe brake caliper.

WARNINGEWA13550

• Cover the brake caliper piston with a rag.Be careful not to get injured when the pis-ton is expelled from the brake caliper.

• Never try to pry out the brake caliper pis-ton.

b. Remove the brake caliper piston dust sealand the brake caliper piston seal.

EAM30032

CHECKING THE FRONT BRAKE CALIPER1. Check:

• Brake caliper piston “1”Rust/scratches/wear Replace the brakecaliper piston.

• Brake caliper cylinder “2”Scratches/wear Replace the brake caliperassembly.

• Brake caliper body “3”Cracks/damage Replace the brake caliperassembly.

• Brake fluid delivery passages

Brake pad pin plug2.5 N·m (0.25 kgf·m, 1.8 lb·ft)

4

5

TR..

6

31

2

FRONT BRAKE

4-18

(brake caliper body)Obstruction Blow out with compressed air.

WARNINGEWA19220

When the brake caliper is disassembled, re-place the brake caliper piston seal and thebrake caliper piston dust seal with new ones.

2. Check:• Brake caliper bracket

Crack/damage Replace.

EAM30033

ASSEMBLING THE FRONT BRAKE CALIPER

WARNINGEWA19230

• Before installation, clean and lubricate theinternal parts. Use new brake fluid forcleaning and lubricating.

• Never use solvents on internal brake com-ponents as they will cause the piston sealsto swell and distort.

• When the brake caliper is disassembled, re-place the brake caliper piston seal and thebrake caliper piston dust seal with newones.

EAM30035

INSTALLING THE FRONT BRAKE CALIPER1. Install:

• Front brake caliper bracket• Front brake caliper

(temporarily)• Copper washer • Brake hose• Union bolt

WARNINGEWA13531

Proper brake hose routing is essential to in-sure safe vehicle operation.

NOTICEECA24460

Make sure that the pipe portion “a” of thebrake hose touches the projection “b” on thebrake caliper.

2. Install:• Front brake caliper• Brake pad spring• Brake pad• Brake pad pin• Brake hose holder

Refer to “CHECKING THE FRONT BRAKEPADS” on page 3-14.

3. Tighten:• Front brake hose holder bolt “1”

TIPMake sure that the brake hose holder “2” is in-stalled with its upper end “a” aligned with thepaint “b” on the brake hose.

4. Pour brake fluid to the brake master cylinder


Front brake caliper bolt28 N·m (2.8 kgf·m, 21 lb·ft)

Front brake hose union bolt30 N·m (3.0 kgf·m, 22 lb·ft)

2

1 1

3

New

TR..


Front brake hose holder bolt9 N·m (0.9 kgf·m, 6.6 lb·ft)

TR..

TR..

2

1

b

a

FRONT BRAKE

4-19

reservoir up to the specified level.

WARNINGEWA13090




NOTICEECA13540


5. Bleed:• Brake system

Refer to “BLEEDING THE HYDRAULICBRAKE SYSTEM” on page 3-15.


The minimum level mark or below Add.Refer to “CHECKING THE BRAKE FLUIDLEVEL” on page 3-14.



EAM30036

REMOVING THE FRONT BRAKE MASTER CYLINDERTIPBefore removing the front brake master cylinder,drain the brake fluid from the entire brake sys-tem.


TIPTo drain any remaining brake fluid, place a con-

tainer under the master cylinder and the end ofthe brake hose.

EAM30037

CHECKING THE FRONT BRAKE MASTER CYLINDER1. Check:

• Brake master cylinder “1”Damage/scratches/wear Replace.

• Brake fluid delivery passages “2”(brake master cylinder body)Obstruction Blow out with compressed air.

2. Check:• Brake master cylinder kit

Damage/scratches/wear Replace.3. Check:

• Brake master cylinder reservoir cap4. Check:


EAM30038

ASSEMBLING THE FRONT BRAKE MASTER CYLINDER

WARNINGEWA13520

• Before installation, all internal brake com-ponents should be cleaned and lubricatedwith clean or new brake fluid.

• Never use solvents on internal brake com-ponents.

1. Wash the brake master cylinder and thebrake master cylinder kit with brake fluid.

2. Install:• Primary cylinder cup “1”• Secondary cylinder cup “2”

(to the brake master cylinder piston “3”)

WARNINGEWA20240

Apply brake fluid to the cylinder cups and in-



1

2

FRONT BRAKE

4-20

stall them as shown. Wrong orientation in in-stallation causes poor braking performance.

3. Install:• Spring “1”

(to the brake master cylinder piston “2”)TIPInstall the spring with a smaller inside diameterto the brake master cylinder piston.

4. Install:• Brake master cylinder kit “1” • Washer “2” • Circlip “3” • Dust boot “4” • Push rod “5”

TIP• Before installation, apply brake fluid to the

brake master cylinder kit.• Before installation, apply silicone grease to the

push rod end.• Use circlip pliers to install the circlip.

EAM30039

INSTALLING THE FRONT BRAKE MASTER CYLINDER1. Install:

• Brake master cylinder “1”

TIP• Install the front brake master cylinder holder

with the “UP” mark “a” facing up.• First, tighten the upper bolt, then the lower bolt.

2. Install:• Copper washer “1” • Brake hose “2”• Union bolt “3”

WARNINGEWA13531


NOTICEECA24470

During installation, bring the brake hose intocontact with the brake master cylinder pro-jection “a” and make its bent portion “b”face downward.

1 2

3

21

3

New

New

Front brake master cylinder hold-er bolt

9 N·m (0.9 kgf·m, 6.6 lb·ft)

Front brake hose union bolt30 N·m (3.0 kgf·m, 22 lb·ft)

TR..

1

a

New

TR..

FRONT BRAKE

4-21

TIPTurn the handlebar toward right and left to makesure that the brake hose does not touch otherparts (e.g., wire harness, cables, leads). Adjustif necessary.

3. Pour brake fluid to the brake master cylinderreservoir up to the specified level.

WARNINGEWA13090




NOTICEECA13540







A softy or spongy feeling Bleed the brake

system.Refer to “BLEEDING THE HYDRAULICBRAKE SYSTEM” on page 3-15.


3

2

b

1

a

REAR BRAKE

4-22

EAM20098

REAR BRAKERemoving the rear brake caliper



1 Protector 1

2 Union bolt 1

3 Copper washer 24 Rear brake hose 1

5 Brake pad pin plug 1

6 Brake pad pin 17 Rear brake pad assembly 2

8 Rear brake caliper bracket 1

9 Brake pad spring 110 Rear brake disc cover 1

11 Rear brake caliper assembly 1

17 N・m (1.7 kgf・m, 13 lb・ft) 2.5 N・m (0.25 kgf・m, 1.8 lb・ft)

30 N・m (3.0 kgf・m, 22 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft) 10 N・m (1.0 kgf・m, 7.4 lb・ft)

11

10

7

97

8

65

1

3

42

REAR BRAKE

4-23

Disassembling the rear brake caliper


1 Brake caliper piston 1

2 Brake caliper piston dust seal 1

3 Brake caliper piston seal 14 Bleed screw 1

1

2

3

4

6 N・m (0.6 kgf・m, 4.4 lb・ft)

REAR BRAKE

4-24

Removing the rear brake master cylinder



1 Union bolt 1

2 Copper washer 23 Brake hose 1

4 Split pin 1

5 Washer 16 Pin 1

7 Brake master cylinder reservoir cap 1

8 Brake master cylinder reservoir diaphragm plate 19 Brake master cylinder reservoir diaphragm 1

10 Rear brake master cylinder 1

1

23

7

5

8

6

9

4

10

30 N・m (3.0 kgf・m, 22 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

1.5 N・m (0.15 kgf・m, 1.1 lb・ft)

REAR BRAKE

4-25

Disassembling the rear brake master cylinder


1 Dust boot 1

2 Circlip 1

3 Push rod 14 Brake master cylinder kit 1

4

3

2

1

New

New

REAR BRAKE

4-26

EAM30040

INTRODUCTION

WARNINGEWA19260

If you need to disassemble the disc brakecomponents, observe the following precau-tions.• Never disassemble the brake components

unless absolutely necessary.• If there is any problem with connections on

the hydraulic brake system, perform thefollowing jobs. Disassemble the brake sys-tem, drain the brake fluid, and clean it. Afterthat, add a suitable amount of brake fluid.Then, bleed it after reassembly.

• Use only brake fluid for washing internalbrake components.

• Use new brake fluid for cleaning the brakecomponents.

• Immediately wipe off the spilled brake fluidto avoid damage to painted surfaces orplastic parts.

• Handle brake fluid with special care not tolet it enter your eyes so that you may notlost your eyesight.

• FIRST AID FOR BRAKE FLUID ENTERINGTHE EYES:

• Flush with water for 15 minutes and get im-mediate medical attention.

EAM30041

CHECKING THE REAR BRAKE DISC1. Check:

• Brake discDamage/galling Replace.

2. Measure:• Brake disc thickness

Measure the brake disc thickness at a few dif-ferent locations.Out of specification Replace.Refer to “CHECKING THE FRONT BRAKEDISC” on page 4-15.

3. Measure:• Brake disc runout

Out of specification Correct the brake discrunout or replace the brake disc.Refer to “CHECKING THE FRONT BRAKEDISC” on page 4-15.

4. Adjust:• Brake disc runout

Refer to “CHECKING THE FRONT BRAKEDISC” on page 4-15.

EAM30523

REPLACING THE REAR BRAKE PADSTIPWhen replacing the brake pads, it is not neces-sary to disconnect the brake hose or disassem-ble the brake caliper.

1. Remove:• Brake pad

a. Remove the protector “1” and the pad pinplug “2”.

b. Loosen the pad pin “3”.c. Remove the rear wheel “4” and the brake

caliper “5”.Refer to “REAR WHEEL” on page 4-7.

d. Remove the pad pin “6” and the brakepads “7”.

Brake disc thickness limit3.5 mm (0.14 in)

Brake disc runout limit (as mea-sured on wheel)

0.15 mm (0.0059 in)

Rear brake disc bolt12 N·m (1.2 kgf·m, 8.9 lb·ft)LOCTITE®

TR..

REAR BRAKE

4-27

2. Measure:• Brake pad wear limit “a”

Out of specification Replace the brakepads as a set.

3. Install:• Brake pad

a. Connect the plastic hose “1” to the bleedscrew “2” and place a container under theend of the plastic hose.

b. Loosen the bleed screw and push thebrake caliper piston in.

WARNINGEWA19170

Do not reuse the drained brake fluid.

c. Tighten the bleed screw.

d. Install the brake pad “3” and the pad pin“4”.

TIP• Install the brake pads with their projections “a”

into the brake caliper recesses “b”.• Temporarily tighten the pad pin at this point.

e. Install the brake caliper “5” and the rearwheel “6”.Refer to “REAR WHEEL” on page 4-7.

f. Tighten the pad pin “7”.

g. Install the pad pin plug “8” and theprotector “9”.

Brake pad lining thickness limit1.0 mm (0.04 in)

Brake caliper bleed screw6 N·m (0.6 kgf·m, 4.4 lb·ft)

76

a

21

TR..



Rear brake caliper protector bolt7 N·m (0.7 kgf·m, 5.2 lb·ft)

34

ab

TR..

5

7

6

TR..

8

9

REAR BRAKE

4-28


Refer to “CHECKING THE BRAKE FLUIDLEVEL” on page 3-14.

5. Check:• Brake pedal operation


EAM30042

REMOVING THE REAR BRAKE CALIPERTIPBefore disassembling the brake caliper, drainthe brake fluid from the entire brake system.


TIPPut the end of the brake hose into a containerand pump out the brake fluid.

EAM30043

DISASSEMBLING THE REAR BRAKE CALIPER1. Remove:

• Brake caliper piston “1”• Brake caliper piston dust seal “2”• Brake caliper piston seal “3”

a. Blow compressed air into the brake hosejoint opening to force out the piston fromthe brake caliper.

WARNINGEWA13550

• Cover the brake caliper piston with a rag.Be careful not to get injured when the pis-ton is expelled from the brake caliper.

• Never try to pry out the brake caliper pis-ton.

b. Remove the brake caliper piston dust sealand the brake caliper piston seal.

EAM30044

CHECKING THE REAR BRAKE CALIPER1. Check:

• Brake caliper piston “1”Rust/scratches/wear Replace the brakecaliper piston.

• Brake caliper cylinder “2”Scratches/wear Replace the brake caliperassembly.

• Brake caliper body “3”Cracks/damage Replace the brake caliperassembly.

• Brake fluid delivery passages(brake caliper body)Obstruction Blow out with compressed air.

WARNINGEWA19270

When the brake caliper is disassembled, re-place the brake caliper piston seal and thebrake caliper piston dust seal with new ones.

2. Check:• Brake caliper bracket

Crack/damage Replace.

EAM30045

ASSEMBLING THE REAR BRAKE CALIPER

WARNINGEWA19280

• Before installation, clean and lubricate theinternal parts. Use new brake fluid for

2 3

1

1

2

3

REAR BRAKE

4-29

cleaning and lubricating.• Never use solvents on internal brake com-

ponents as they will cause the piston sealsto swell and distort.

• When the brake caliper is disassembled, re-place the brake caliper piston seal and thebrake caliper piston dust seal with newones.

EAM30047

INSTALLING THE REAR BRAKE CALIPER1. Install:

• Rear brake caliper• Rear brake caliper bracket

2. Install:• Rear wheel

Refer to “REAR WHEEL” on page 4-7.• Copper washer • Brake hose• Union bolt

WARNINGEWA13531


NOTICEECA24490

Make sure that a bend in its pipe portion “a”is directed as shown and the brake hosetouches the projection “b” on the brake cali-per.

3. Install:• Brake pad spring• Brake pad• Brake pad pin• Brake pad pin plug

Refer to “CHECKING THE REAR BRAKEPADS” on page 3-15.

4. Pour brake fluid to the brake fluid reservoir upto the specified level.

WARNINGEWA13090




NOTICEECA13540








EAM30048

REMOVING THE REAR BRAKE MASTER CYLINDERTIPBefore removing the rear brake master cylinder,drain the brake fluid from the entire brake sys-


Rear brake hose union bolt30 N·m (3.0 kgf·m, 22 lb·ft)

New

TR..

b

b a




TR..

REAR BRAKE

4-30

tem.


TIPTo drain any remaining brake fluid, place a con-tainer under the master cylinder and the end ofthe brake hose.

EAM30049

CHECKING THE REAR BRAKE MASTER CYLINDER1. Check:

• Brake master cylinder “1”Damage/scratches/wear Replace.

• Brake fluid delivery passages “2”(brake master cylinder body)Obstruction Blow out with compressed air.

2. Check:• Brake master cylinder kit


• Master cylinder reservoir capCrack/damage Replace.

• Brake master cylinder reservoir diaphragmholder

• Brake master cylinder reservoir diaphragmCrack/damage Replace.

4. Check:• Brake hose

Cracks/damage/wear Replace.

EAM30050

ASSEMBLING THE REAR BRAKE MASTER CYLINDER

WARNINGEWA13520

• Before installation, all internal brake com-ponents should be cleaned and lubricatedwith clean or new brake fluid.

• Never use solvents on internal brake com-ponents.

1. Wash the brake master cylinder and thebrake master cylinder kit with brake fluid.

2. Install:• Primary cylinder cup “1”• Secondary cylinder cup “2”

(to the brake master cylinder piston “3”)

WARNINGEWA19300

Apply brake fluid to the cylinder cups and in-stall them as shown. Wrong orientation in in-stallation causes poor braking performance.

3. Install:• Spring “1”

(to the brake master cylinder piston “2”)TIPInstall the spring with a smaller inside diameterto the brake master cylinder piston.

1 2


2

3

1

2

3

1

1 2

REAR BRAKE

4-31

4. Install:• Brake master cylinder kit “1” • Push rod “2”• Circlip “3” • Dust boot “4”

TIP• Before installation, apply brake fluid to the

brake master cylinder kit.• Before installation, apply silicone grease to the

push rod end.• Use circlip pliers to install the circlip.

EAM30051

INSTALLING THE REAR BRAKE MASTER CYLINDER1. Install:

• Copper washer • Brake hose• Union bolt

WARNINGEWA13531


NOTICEECA24500

Make sure that the pipe portion of the brakehose touches the projection “a” on the brakecaliper.

2. Pour brake fluid to the brake fluid reservoir up

to the specified level.

WARNINGEWA13090




NOTICEECA24510








Rear brake hose union bolt30 N·m (3.0 kgf·m, 22 lb·ft)

New

New

1 3

4

2

New New

New

TR..

a


HANDLEBAR

4-32

EAM20099

HANDLEBARRemoving the handlebar


Number plate Refer to “GENERAL CHASSIS” on page 4-1.

1 Clutch cable 1

2 Clutch lever holder 1

3 Engine stop switch 14 Brake master cylinder 1

5 Throttle cable cap 1

6 Throttle cable 17 Right grip 1

8 Cap cover 1

9 Collar 110 Left grip 1

11 Upper handlebar holder 2

12 Handlebar 113 Lower handlebar holder 2

1 2

12

11

13

4

7

9

5

6

3

10

8

0.5 N・m (0.05 kgf・m, 0.37 lb・ft)

9 N・m (0.9 kgf・m, 6.6 lb・ft)

28 N・m (2.8 kgf・m, 21 lb・ft)

5 N・m (0.5 kgf・m, 3.7 lb・ft)

0.5 N・m (0.05 kgf・m, 0.37 lb・ft)

4.8 N・m (0.48 kgf・m, 3.5 lb・ft)

4.3 N・m (0.43 kgf・m, 3.2 lb・ft)

40 N・m (4.0 kgf・m, 30 lb・ft)

HANDLEBAR

4-33

EAM30052

REMOVING THE HANDLEBAR1. Stand the vehicle upright on a level surface.

WARNINGEWA13120


2. Remove:• Grip “1”

TIPBlow in compressed air between the handlebaror tube guide and the grip. Then remove the gripwhich has become loose.

3. Remove:• Throttle cable housing “1”• Throttle grip “2”

TIPWhile removing the throttle cable housing, pullback the rubber cover “3”.

EAM30053

CHECKING THE HANDLEBAR1. Check:

• HandlebarBends/cracks/damage Replace.

WARNINGEWA13690

Do not attempt to straighten a bent handle-bar as this may dangerously weaken it.

EAM30054

INSTALLING THE HANDLEBAR1. Stand the vehicle upright on a level surface.

WARNINGEWA13120


2. Install:• Lower handlebar holder “1”• Washer “2”• Lower handlebar holder nut “3”

TIP• Install the lower handlebar holders with them

side having the greater distance “a” from themounting bolt center facing forward.

• Apply the lithium soap base grease on thethread of the lower handlebar holders.

• Installing the lower handlebar holders in the re-verse direction allow the front-to-rear offsetamount of the handlebar position to bechanged.

• Do not tighten the nuts yet.

3. Install:• Handlebar “1”• Upper handlebar holder “2”• Upper handlebar holder bolt “3”

TIP• The upper handlebar holders should be in-

stalled with the punch marks “a” facing for-ward.

• Install the handlebar so that the marks “b” are

1

G088916

1 32

Upper handlebar holder bolt28 N·m (2.8 kgf·m, 21 lb·ft)

1

2

3

TR..

HANDLEBAR

4-34

in place on both sides.• Install the handlebar so that the projection “c”

of the upper handlebar holders is positioned atthe mark on the handlebar as shown.

• First tighten the bolts on the front side of theupper handlebar holder, and then tighten thebolts on the rear side.

4. Tighten:• Lower handlebar holder nut “1”

5. Install:• Left grip “1”

Apply the adhesive to the handlebar “2”.TIP• Before applying the adhesive, wipe off grease

or oil on the handlebar surface “a” with a lac-quer thinner.

• Install the left grip to the handlebar so that theline “b” between the two arrow marks facesstraight upward.

6. Install:• Engine stop switch “1”

• Clutch lever holder “2”• Clutch lever holder bolt “3”

• Clamp “4”TIP• The engine stop switch, clutch lever holder and

clamp should be installed according to the di-mensions shown.

Lower handlebar holder nut40 N·m (4.0 kgf·m, 30 lb·ft)

Engine stop switch screw0.5 N·m (0.05 kgf·m, 0.37 lb·ft)

Clutch lever holder bolt5 N·m (0.5 kgf·m, 3.7 lb·ft)

Clutch lever nut4.8 N·m (0.48 kgf·m, 3.5 lb·ft)

TR..

TR..

TR..

HANDLEBAR

4-35

• Pass the engine stop switch lead in the middleof the clutch lever holder.

7. Install:• Clutch cable “1”

TIPApply the lithium soap base grease on the clutchcable end.

8. Adjust:• Clutch lever free play

Refer to “ADJUSTING THE CLUTCH LEVERFREE PLAY” on page 3-7.

9. Install:• Right grip “1”

Apply the adhesive on the tube guide “2”.TIP• Before applying the adhesive, wipe off grease

or oil on the tube guide surface “a” with a lac-quer thinner.

• Align the mating mark “b” on the right grip withthe slot “c” in the tube guide.

10.Install:• Grip cap (upper) “1”• Grip cap (lower) “2”• Grip cap bolt “3”

TIPTemporarily tighten the grip cap bolts.

11.Install:• Collar “1”• Grip cap cover “2”• Throttle grip “3”

TIP• Apply the lithium soap base grease on the

throttle grip sliding surface.• Tighten the grip cap bolts temporarily without

the throttle being fixed to the handlebar.

0 mm(0 in)

0 mm(0 in)

1

HANDLEBAR

4-36

12.Install:• Throttle cable “1”

(to tube guide “2”)TIPApply the lithium soap base grease on the throt-tle cable end and tube guide cable winding por-tion.

13.Install:• Roller “1”• Collar “2”

TIP• Apply the lithium soap base grease on the roll-

er sliding surface and cable guide.• Install the roller so that the “UPPER” mark “a”

faces upward.• Pass the throttle cable in the groove “b” in the

roller.

14.Install:• Throttle cable cap “1”• Throttle cable cap screw “2”

15.Adjust:• Throttle grip free play

Refer to “CHECKING THE THROTTLEGRIP” on page 3-5.

16.Install:• Cap cover “1”

17.Install:• Brake master cylinder “1”• Brake master cylinder holder “2”• Front brake master cylinder holder bolt “3”

TIP• Install the holder so that the arrow mark “a” fac-

es upward.• First tighten the bolt on the upper side of the

brake master cylinder holder, and then tightenthe bolt on the lower side.

1

2

3

1

2

12

a

b

Throttle cable cap screw0.5 N·m (0.05 kgf·m, 0.37 lb·ft)

Front brake master cylinder hold-er bolt

9 N·m (0.9 kgf·m, 6.6 lb·ft)

TR..

TR..

HANDLEBAR

4-37

18.Install:• Grip cap bolt “1”

WARNINGEWA21080

After tightening the bolts, check that thethrottle grip “2” moves smoothly. If it doesnot, retighten the bolts for adjustment.

Grip cap bolt3.8 N·m (0.38 kgf·m, 2.8 lb·ft)T

R..

FRONT FORK

4-38

EAM20100

FRONT FORKRemoving the front fork legs



Front wheel Refer to “FRONT WHEEL” on page 4-3.

Front brake caliper Refer to “FRONT BRAKE” on page 4-11.


1 Protector 1

2 Upper bracket pinch bolt 2 Loosen.

3 Damper assembly 1 Loosen.4 Lower bracket pinch bolt 2 Loosen.

5 Front fork leg 1

5 N・m (0.5 kgf・m, 3.7 lb・ft) 5 N・m (0.5 kgf・m, 3.7 lb・ft)

9 N・m (0.9 kgf・m, 6.6 lb・ft)

21 N・m (2.1 kgf・m, 15 lb・ft)

21 N・m (2.1 kgf・m, 15 lb・ft)

3

2

4

5

1

FRONT FORK

4-39

Disassembling the front fork leg


1 Adjuster 1

2 Fork spring 1

3 Damper adjusting rod 14 Dust seal 1

5 Stopper ring 1

6 Inner tube 17 Outer tube 1

8 Piston metal 1

9 Protector guide 110 Slide metal 1

11 Washer 1

12 Oil seal 113 Base valve 1

14 Damper assembly 1

15 Upper spring seat 1

29 N・m (2.9 kgf・m, 21 lb・ft)

30 N・m (3.0 kgf・m, 22 lb・ft)

29 N・m (2.9 kgf・m, 21 lb・ft)

55 N・m (5.5 kgf・m, 41 lb・ft) 1.3 N・m (0.13 kgf・m, 0.95 lb・ft)

10

7

15

2

14

6

1

45

8

11

12

3

13

9

FRONT FORK

4-40

EAM30055

REMOVING THE FRONT FORK LEGS1. Use a maintenance stand to raise the front


WARNINGEWA13120


TIPRecord the adjusting screw setting position be-fore loosening the adjuster and the base valve.

2. Loosen:• Upper bracket pinch bolt• Damper assembly• Lower bracket pinch bolt

WARNINGEWA20350

Before loosening the upper and lower brack-et pinch bolts, support the front fork leg.

TIPBefore removing the front fork leg from the vehi-cle, loosen the damper assembly “1” with thecap bolt ring wrench “2”.

3. Remove:• Front fork leg

EAM30056

DISASSEMBLING THE FRONT FORK LEGS1. Drain:

• Fork oil2. Remove:

• Adjuster “1”(from the inner tube)

TIP• While compressing the inner tube “2”, set the

cap bolt ring wrench “4” between the inner tubeand locknut “3”.

• Hold the locknut and remove the adjuster.

NOTICEECA24520

Do not remove the locknut as the damper rodmay go into the damper assembly and not betaken out.

3. Remove:• Dust seal “1”• Stopper ring “2”

(with a flat-head screwdriver)

NOTICEECA14180

Do not scratch the inner tube.

4. Remove:• Inner tube “1”

a. Push in slowly “a” the inner tube just be-fore it bottoms out and then pull it backquickly “b”.

b. Repeat this step until the inner tube can bepulled out from the outer tube.

Cap bolt ring wrench90890-01501

Cap bolt ring wrenchYM-01501

1 2



1

23

4

G088920

1

2

FRONT FORK

4-41

5. Remove:• Base valve “1”

(from the damper assembly)TIPHold the damper assembly with the cap bolt ringwrench “2” and use the cap bolt wrench “3” to re-move the base valve.

EAM30057

CHECKING THE FRONT FORK LEGS1. Check:

• Inner tube surfaceScratches Repair or replace.Use #1000 grit wet sandpaper.Damaged oil lock piece Replace.

• Inner tube bendsOut of specification Replace.Use the dial gauge.

TIPThe bending value is shown by one half of the

dial gauge reading.

WARNINGEWA13650

Do not attempt to straighten a bent innertube as this may dangerously weaken it.

2. Check:• Outer tube

Scratches/wear/damage Replace.3. Measure:

• Fork spring free length “a”Out of specification Replace.

4. Check:• Damper assembly “1”

Bend/damage Replace.• O-ring “2”

Wear/damage Replace.

NOTICEECA14200

• The front fork leg has a built-in damper ad-justing rod and a very sophisticated inter-nal construction, which are particularlysensitive to foreign material.

• When disassembling and assembling thefront fork leg, do not allow any foreign ma-terial to enter the front fork.

5. Check:• Base valve “1”


Cap bolt wrench90890-01500

Cap bolt wrenchYM-01500



Inner tube bending limit0.2 mm (0.01 in)

1

2

3

Fork spring free length limit449.0 mm (17.68 in)

G088921

2

1

FRONT FORK

4-42

Contamination Clean.• O-ring “2”

Wear/damage Replace.• Piston metal “3”

Wear/damage Replace.• Fork spring “4”

Damage/fatigue Replace base valve.• Air bleed screw “5”


6. Check:• Upper spring seat “1”

(contacting surface “a”)Wear/damage Replace.

7. Check:• Adjuster “1”• O-ring “2”


EAM30058

ASSEMBLING THE FRONT FORK LEGS

WARNINGEWA13660

• Make sure the oil levels in both front fork

legs are equal.• Uneven oil levels can result in poor han-

dling and a loss of stability.

TIP• When assembling the front fork leg, be sure to

replace the following parts:• Inner tube bushing• Slide metal• Oil seal• Copper washer

• Before assembling the front fork leg, makesure that all of the components are clean.

1. Stretch the damper assembly fully.2. Fill:

• Damper assembly

NOTICEECA24530

• Be sure to use the recommended oil. Otheroils may have an adverse effect on frontfork performance.

• When disassembling and assembling thefront fork leg, take care not to allow any for-eign material to enter the front fork.

3. After filling, pump the damper assembly “1”slowly up and down (about 200 mm (7.9 in)stroke) several times to bleed the damper as-sembly of air.

TIPAvoid excessive full stroke. A stroke of 200 mm(7.9 in) or more will cause air to enter. In thiscase, repeat the steps (1) to (3).

4. Measure:• Oil level (left and right) “a”


New

a

1

New

New

1

2

Recommended oilYamaha Suspension Oil S1

Standard oil amount205 cm³ (6.93 US oz, 7.21 Imp.oz)

1

FRONT FORK

4-43

5. Tighten:• Locknut “1”

TIPFully finger tighten the locknut onto the damperassembly.

6. Loosen:• Compression damping force adjuster “1”

TIP• Before loosening the damping force adjuster,

record the setting position.• Unless the damping force adjuster is fully loos-

ened, correct damping characteristic cannot beobtained after installation.

7. Install:• Base valve “1”

(to the damper assembly “2”)TIPFirst bring the damper rod pressure to a maxi-mum. Then install the base valve while releasingthe damper rod pressure.

8. Check:• Damper assembly

Not fully stretched Repeat the steps (1) to(7).

9. Tighten:• Base valve “1”

TIPHold the damper assembly with the cap bolt ringwrench “2” and use the cap bolt wrench “3” totighten the base valve.

Standard oil level145–148 mm (5.71–5.83 in)From top of fully stretched damper assembly.

a

Base valve (front fork)29 N·m (2.9 kgf·m, 21 lb·ft)

Cap bolt wrench90890-01500

Cap bolt wrenchYM-01500



1

2

TR..

FRONT FORK

4-44

10.After filling, pump the damper assembly “1”slowly up and down more than 10 times todistribute the fork oil.

11.While protecting the damper assembly “1”with a cloth and compressing fully, allow ex-cessive oil to overflow on the base valve side.

NOTICEECA24540

Take care not to damage the damper assem-bly.

12.Allow the overflowing oil to escape at the hole“a” in the damper assembly.

TIPThe overflow measures about 10 cm³ (0.34US oz, 0.35 Imp.oz).

13.Check:• Damper assembly smooth movement

Tightness/binding/rough spots Repeat thesteps (1) to (12).

14.Install:• Dust seal “1” • Stopper ring “2”• Oil seal “3” • Washer “4”• Slide metal “5”

(to the inner tube “6”)

NOTICEECA24550

Make sure that the numbered side of the oilseal faces bottom side.

TIP• Apply the lithium-soap-based grease on the

dust seal lip and oil seal lip.• Apply the fork oil on the inner tube.• When installing the oil seal, use vinyl seat with

fork oil applied to protect the oil seal lip.

1

2

3

1

1

a

New

New

New

LS

FRONT FORK

4-45

15.Install:• Piston metal “1”

TIPInstall the piston metal onto the slot on innertube.

16.Install:• Outer tube “1”


17.Install:• Slide metal “1” • Washer “2”

(to the outer tube)TIPPress the slide metal into the outer tube with forkseal driver “3”.

18.Install:• Oil seal “1”

TIPUsing a fork seal driver “2”, press the oil seal inuntil the stopper ring groove fully appears.

19.Install:• Stopper ring “1”

TIPFit the stopper ring correctly in the groove in theouter tube.

20.Install:• Dust seal “1”

TIPApply lithium-soap-based grease on the innertube.

Fork seal driver90890-01502

Fork seal driver (48)YM-A0948

G088922

New

New

Fork seal driver90890-01502

Fork seal driver (48)YM-A0948

1

2

3

G088923

New

1

2

G088924

1

G088925

New

FRONT FORK

4-46

21.Check:• Inner tube smooth movement

Tightness/binding/rough spots Repeat thesteps (14) to (20).

22.Measure:• Distance “a”

Out of specification Turn into the locknut.

23.Install:• Upper spring seat “1”• Fork spring “2”

(to the damper assembly “3”)TIPInstall the upper spring seat with its larger dia.end “a” facing the fork spring.

24.Install:• Damper assembly “1”


NOTICEECA24560

Allow the damper assembly to slide slowlydown the inner tube until it contacts the bot-tom of the inner tube. Be careful not to dam-age the inner tube.

25.Loosen:• Rebound damping force adjuster “1”

TIP• Before loosening the damping force adjuster,

record the setting position.• Unless the damping force adjuster is fully loos-

ened, correct damping characteristic cannot beobtained after installation.

26.Install:• Damper adjusting rod “1”• Copper washer “2” • Adjuster “3”

Distance “a”16 mm (0.63 in) or moreBetween the damper assembly “1” bottom and locknut “2” bot-tom.

12

a

1 2

3 a

1

2

1

New

FRONT FORK

4-47

(to the damper assembly “4”)TIP• While compressing the inner tube “5”, set the

cap bolt ring wrench “7” between the inner tubeand locknut “6”.

• Fully finger tighten the adjuster onto the damp-er assembly.

27.Measure:• Gap “a” between the adjuster “1” and the

locknut “2”Out of specification Retighten and readjustthe locknut.

TIPIf it is installed with a gap out of specification,correct damping force cannot be obtained.

28.Tighten:• Adjuster (damper assembly) “1”

TIPHold the locknut “2” and tighten the adjuster.

29.Install:• Adjuster “1”

(to the inner tube)

30.Fill:• Front fork leg

NOTICEECA24570

• Be sure to use the recommended oil. Otheroils may have an adverse effect on frontfork performance.

• When disassembling and assembling thefront fork leg, do not allow any foreign ma-terial to enter the front fork.



Gap “a” between the adjuster and the locknut

0.5–1.0 mm (0.02–0.04 in)

Adjuster (damper assembly)29 N·m (2.9 kgf·m, 21 lb·ft)

1

2

a

TR..

Adjuster55 N·m (5.5 kgf·m, 41 lb·ft)LOCTITE®



Extent of adjustment210–365 cm³ (7.1–12.3 US oz, 7.4–12.9 Imp.oz)

TR..

1

FRONT FORK

4-48

31.Install:• Damper assembly “1”

(to the outer tube)TIPTemporarily tighten the damper assembly.

32.Install:• Protector guide “1”

EAM30059

INSTALLING THE FRONT FORK LEGS1. Install:

• Front fork “1”TIP• Temporarily tighten the pinch bolts (lower

bracket).• Do not tighten the pinch bolts (upper bracket)

yet.

2. Tighten:• Damper assembly “1”

TIPUse the cap bolt ring wrench “2” to tighten thedamper assembly.

3. Adjust:• Front fork top end “a”

4. Tighten:• Upper bracket pinch bolt “1”

1

Damper assembly (front fork)30 N·m (3.0 kgf·m, 22 lb·ft)



Front fork top end (standard) “a”5 mm (0.2 in)

TR..

2

1

a

FRONT FORK

4-49

• Lower bracket pinch bolt “2”

WARNINGEWA19320

Tighten the lower bracket to specifiedtorque. If torqued too much, it may cause thefront fork to malfunction.

5. Install:• Protector “1”• Front fork protector bolt “2”

6. Adjust:• Rebound damping force

TIPTurn in the damping adjuster “1” finger-tight andthen turn out to the originally set position.

7. Adjust:• Compression damping force

TIPTurn in the damping adjuster “1” finger-tight andthen turn out to the originally set position.

Upper bracket pinch bolt21 N·m (2.1 kgf·m, 15 lb·ft)

Lower bracket pinch bolt21 N·m (2.1 kgf·m, 15 lb·ft)

Front fork protector bolt5 N·m (0.5 kgf·m, 3.7 lb·ft)

TR..

TR..

TR..

1

2

1

1

STEERING HEAD

4-50

EAM20101

STEERING HEADRemoving the lower bracket




Handlebar Refer to “HANDLEBAR” on page 4-32.

1 Front fender 12 Steering stem nut 1

3 Front fork leg 2

4 Upper bracket 15 Steering ring nut 1

6 Lower bracket 1

7 Bearing race cover 18 Upper bearing 1

9 Lower bearing 1

10 Bearing race 2

5

4

2

10

7

8

9

3

6

1

10 N・m (1.0 kgf・m, 7.4 lb・ft)

3.8 N・m (0.38 kgf・m, 2.8 lb・ft)

21 N・m (2.1 kgf・m, 15 lb・ft)

145 N・m (14.5 kgf・m, 107 lb・ft)

21 N・m (2.1 kgf・m, 15 lb・ft)

1st 2nd

38 N・m (3.8 kgf・m, 28 lb・ft)7 N・m (0.7 kgf・m, 5.2 lb・ft)

STEERING HEAD

4-51

EAM30060

REMOVING THE LOWER BRACKET1. Use a maintenance stand to raise the front


WARNINGEWA13120


2. Remove:• Ring nut “1”

TIPRemove the ring nut with the steering nutwrench “2”.

WARNINGEWA13730

Securely support the lower bracket so thatthere is no danger of it falling.

EAM30061

CHECKING THE STEERING HEAD1. Wash with kerosene:

• Bearing• Bearing race

2. Check:• Bearing• Bearing race

Damage/pitting Replace.3. Replace:

• Bearing• Bearing race

a. Remove the bearing race from the steer-ing head pipe “1” with a long rod “2” and ahammer.

b. Remove the bearing race from the lowerbracket “3” with a chisel “4” and a hammer.

c. Install a new bearing race.

NOTICEECA14270

If the bearing race is not installed properly,the steering head pipe could be damaged.

TIPAlways replace the bearing and the bearing raceas a set.

4. Check:• Upper bracket• Lower bracket

(along with the steering stem)Bends/cracks/damage Replace.

EAM30062

INSTALLING THE STEERING HEAD1. Install:

• Lower bearing “1”TIPApply the lithium-soap-based grease on the dustseal lip and bearing inner circumference.

2. Install:• Bearing race

Steering nut wrench90890-01403

Exhaust flange nut wrenchYU-A9472 G088933

G088934

STEERING HEAD

4-52

• Upper bearing “1”• Bearing race cover “2”

TIPApply the lithium-soap-based grease on thebearing and bearing race cover lip.

3. Install:• Lower bracket “1”

TIPApply the lithium-soap-based grease on thebearing, the portion “a” and thread of the steer-ing stem.

4. Install:• Steering ring nut “1”

TIPInstall the steering ring nut with its stepped side“a” facing downward.

Tighten the steering ring nut with a steeringnut wrench “2”.Refer to “CHECKING AND ADJUSTINGTHE STEERING HEAD” on page 3-17.

5. Check the steering stem by turning this lockto lock. If there is any binding, remove thesteering stem and check the steering bear-ing.

6. Install:• Washer “1”

7. Install:• Front fork “1”• Upper bracket “2”

TIP• Temporarily tighten the lower bracket pinch

bolts.• Do not tighten the upper bracket pinch bolts

yet.

Steering ring nut7 N·m (0.7 kgf·m, 5.2 lb·ft)

LS

1

aLSLS

TR..

STEERING HEAD

4-53

8. Install:• Steering stem nut “1”

TIPApply the lithium-soap-based grease to the con-tact surface of the steering stem nut when in-stalling.

9. After tightening the nut, check the steering forsmooth movement. If not, adjust the steeringby loosening the steering ring nut little by lit-tle.

10.Adjust:• Front fork top end “a”

11.Tighten:• Upper bracket pinch bolt “1”

• Lower bracket pinch bolt “2”

WARNINGEWA19330

Tighten the lower bracket to specifiedtorque. If torqued too much, it may cause thefront fork to malfunction.

Steering stem nut145 N·m (14.5 kgf·m, 107 lb·ft)

Front fork top end (standard) “a”5 mm (0.2 in)

TR..

a

Upper bracket pinch bolt21 N·m (2.1 kgf·m, 15 lb·ft)

Lower bracket pinch bolt21 N·m (2.1 kgf·m, 15 lb·ft)

TR..

TR..

REAR SHOCK ABSORBER ASSEMBLY

4-54

EAM20102

REAR SHOCK ABSORBER ASSEMBLYRemoving the rear shock absorber assembly


Seat Refer to “GENERAL CHASSIS” on page 4-1.

Silencer Refer to “ENGINE REMOVAL” on page 5-1.

1 Air filter case joint clamp 1

2 Rear frame 13 Rear shock absorber assembly lower bolt 1

4 Rear shock absorber assembly upper bolt 1

5 Rear shock absorber assembly 16 Locknut 1

7 Adjusting nut 1

8 Lower spring guide 19 Upper spring guide 1

10 Spring 1

11 Dust seal 412 Collar 4

13 Bearing 1

14 Bushing 1

412

1211

11

14

56

9

8

3

1 2

1312

1211

11

7

10

29 N・m (2.9 kgf・m, 21 lb・ft)

32 N・m (3.2 kgf・m, 24 lb・ft)

56 N・m (5.6 kgf・m, 41 lb・ft)

2.3 N・m (0.23 kgf・m, 1.7 lb・ft)

53 N・m (5.3 kgf・m, 39 lb・ft)


4-55

Disassembling the relay arm


1 Relay arm 1

2 Connecting arm 1

3 Collar 34 Oil seal 6

5 Washer 8

6 Bearing 6

80 N・m (8.0 kgf・m, 59 lb・ft)

46

3

6

65

56

1

4

43

5

2

4

4

55

4 5

3

6

6


4-56

EAM30063

HANDLING THE REAR SHOCK ABSORBER

WARNINGEWA13740

This rear shock absorber contains highlycompressed nitrogen gas. Before handlingthe rear shock absorber, read and make sureyou understand the following information.The manufacturer cannot be held responsi-ble for property damage or personal injurythat may result from improper handling ofthe rear shock absorber.• Do not tamper or attempt to open the rear

shock absorber.• Do not subject the rear shock absorber to

an open flame or any other source of highheat. High heat can cause an explosion dueto excessive gas pressure.

• Do not deform or damage the rear shockabsorber in any way. Rear shock absorberdamage will result in poor damping perfor-mance.

TIPA break-in is required up to about 50 km of run-ning.

EAM30064

DISPOSING OF A REAR SHOCK ABSORBERBefore disposing the rear shock absorber, besure to extract the nitrogen gas from valve “1”.

WARNINGEWA19340

• Wear protective glasses to prevent youreyes from damage due to possible gas ormetal chips scattered.

• To dispose of a damaged or a worn-out rearshock absorber, take the unit to yourYamaha dealer for this disposal procedure.

EAM30065

REMOVING THE REAR SHOCK ABSORBER ASSEMBLY1. Use a maintenance stand to raise the rear


WARNINGEWA13120


2. Remove:• Rear shock absorber assembly lower bolt “1”

TIPWhile removing the rear shock absorber assem-bly lower bolt, hold the swingarm so that it doesnot drop down.

3. Remove:• Rear shock absorber assembly upper bolt• Rear shock absorber assembly

EAM30067

CHECKING THE REAR SHOCK ABSORBER ASSEMBLY1. Check:

• Rear shock absorber rodBends/damage Replace the rear shockabsorber assembly.

• Rear shock absorberGas leaks/oil leaks Replace the rear shockabsorber assembly.

• SpringDamage/wear Replace.

• Spring guideDamage/wear Replace.

• BearingDamage/wear Replace.

• BoltBends/damage/wear Replace.

EAM30068

CHECKING THE CONNECTING ARM AND RELAY ARM1. Check:

• Connecting arm• Relay arm


• Bearing• Collar

1


4-57

Damage/pitting/scratches Replace thebearings and collars as a set.

3. Check:• Oil seal

Damage/pitting Replace.

EAM30069

INSTALLING THE RELAY ARM1. Lubricate:

• Oil seal• Bearing• Washer• Collar

2. Install:• Bearing “1”• Washer “2”• Oil seal “3”

(to relay arm “4”)

3. Install:• Bearing “1”• Oil seal “2”

(to connecting arm “3”)

EAM30070

INSTALLING THE REAR SHOCK ABSORBER ASSEMBLY1. Lubricate:

• Bearing (lower side)• Dust seal

NOTICEECA24580

Do not apply the grease to the bearing outerrace because it will wear the rear shock ab-sorber surface on which the bearing is pressfitted.

2. Lubricate:• O-ring

3. Install:• Bearing• Stopper ring

(to rear shock absorber assembly (upperside))

TIP• Install the bearing parallel until the stopper ring

groove appears by pressing its outer race.• After installing the stopper ring, push back the

bearing until it contacts the stopper ring.

4. Install:• Bearing “1”• Bushing “2”• Collar “3”• Dust seal “4”

(to rear shock absorber assembly (lowerside))

TIPInstall the dust seals with their lips facing inward.

Recommended lubricantMolybdenum disulfide grease

Installed depth “a”0 mm (0 in)

Installed depth “a”0 mm (0 in)

New

4 2

3

3a

1

1

2

2

3

3

1

2

New

3

a

1

1

2

a

2



Installed depth “a”4.25 mm (0.17 in)

New


4-58

5. Lubricate:• Connecting arm and frame bolt• Relay arm and connecting arm bolt• Relay arm and swingarm bolt

(circumference and threaded portion)• Rear shock absorber assembly upper bolt• Rear shock absorber assembly lower bolt

6. Install:• Rear shock absorber assembly

TIP• When installing the rear shock absorber as-

sembly, lift up the swingarm.• Install the rear shock absorber assembly upper

bolt, and connecting arm bolt (frame side) fromthe right.

• Install the rear shock absorber assembly lowerbolts, connecting arm bolt (relay arm side), andrelay arm bolt (swingarm side) from the left.

7. Tighten:• Rear shock absorber assembly upper nut

• Connecting arm nut (frame side)

• Connecting arm nut (relay arm side)

• Relay arm nut (swingarm side)

• Rear shock absorber assembly lower nut

8. Install:• Rear frame “1”• Rear frame bolt (upper) “2”

• Rear frame bolt (lower) “3”

9. Tighten:• Air filter case joint clamp “1”


Rear shock absorber assembly upper nut

56 N·m (5.6 kgf·m, 41 lb·ft)

Connecting arm nut (frame side)80 N·m (8.0 kgf·m, 59 lb·ft)

Connecting arm nut (relay arm side)

80 N·m (8.0 kgf·m, 59 lb·ft)

Relay arm nut (swingarm side)70 N·m (7.0 kgf·m, 52 lb·ft)

TR..

TR..

TR..

TR..

Rear shock absorber assembly lower nut

53 N·m (5.3 kgf·m, 39 lb·ft)

Rear frame bolt (upper)32 N·m (3.2 kgf·m, 24 lb·ft)

Rear frame bolt (lower)29 N·m (2.9 kgf·m, 21 lb·ft)

Air filter case joint clamp2.3 N·m (0.23 kgf·m, 1.7 lb·ft)

TR..

TR..

TR..

TR..

SWINGARM

4-59

EAM20103

SWINGARMRemoving the swingarm



Brake hose holder Refer to “REAR BRAKE” on page 4-22.

Rear brake caliper Refer to “REAR BRAKE” on page 4-22.

Bolt (brake pedal)Drive chain

1 Collar 2

2 Oil seal 23 Thrust bearing 2

4 Bushing 2


6 N・m (0.6 kgf・m, 4.4 lb・ft)

2.0 N・m (0.20 kgf・m, 1.5 lb・ft)

70 N・m (7.0 kgf・m, 52 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

85 N・m (8.5 kgf・m, 63 lb・ft)

56

6 1

1

23

6

3

2

6

5

4

4

SWINGARM

4-60

EAM30071

REMOVING THE SWINGARM1. Use a maintenance stand to raise the rear


WARNINGEWA13120


2. Measure:• Swingarm side play• Swingarm vertical movement

a. Measure the tightening torque of the pivotshaft nut.

b. Check the swingarm side play “A” by mov-ing the swingarm from side to side.If the swingarm has side-to-side play,check the bushings, the bearings, and thecollars.

c. Check the swingarm vertical movement“B” by moving the swingarm up and down. If swingarm vertical movement is notsmooth or if there is binding, check thebushings, the bearings, and the collars.

EAM30073

CHECKING THE SWINGARM1. Check:

• SwingarmBends/cracks/damage Replace.

2. Check:• Pivot shaft

Roll the pivot shaft on a flat surface.Bends Replace.

WARNINGEWA13770

Do not attempt to straighten a bent pivotshaft.

3. Wash with kerosene:• Pivot shaft• Bushing• Collar

• Bearing4. Check:

• Oil sealDamage Replace.

• Bearing• Thrust bearing• Bushing

Free play exists/unsmooth revolution/rust Replace bearing and bushing as a set.

EAM30074

INSTALLING THE SWINGARM1. Lubricate:

• Bearing• Bushing• Collar• Thrust bearing• Oil seal • Pivot shaft

2. Install:• Bearing “1”• Oil seal “2”

(to the swingarm)

TIPFirst install the outer and then the inner bearingsto a specified depth from inside.

3. Install:• Swingarm

TIPInstall the pivot shaft from the right.

Pivot shaft nut85 N·m (8.5 kgf·m, 63 lb·ft)T

R..

BA

BA

G088936


Installed depth “a”0–0.5 mm (0–0.02 in)

Installed depth “b”6.5 mm (0.26 in)

Pivot shaft nut85 N·m (8.5 kgf·m, 63 lb·ft)

New

New

22 211

a aa

bb

a

New NewNew

TR..

SWINGARM

4-61

4. Install:• Rear wheel

Refer to “REAR WHEEL” on page 4-7.5. Adjust:

• Drive chain slackRefer to “DRIVE CHAIN SLACK” on page3-16.


48.0–58.0 mm (1.89–2.28 in)

CHAIN DRIVE

4-62

EAM20104

CHAIN DRIVERemoving the drive chain


Drive sprocket Refer to “ENGINE REMOVAL” on page 5-1.1 Drive chain 1

2 Drive sprocket cover 1

3 Bracket 14 Drive sprocket nut 1

5 Lock washer 1

6 Drive sprocket 1

1

2

(2)

34

5

6

5 N・m (0.5 kgf・m, 3.7 lb・ft)

75 N・m (7.5 kgf・m, 55 lb・ft)

CHAIN DRIVE

4-63

EAM30075

REMOVING THE DRIVE CHAIN1. Stand the vehicle on a level surface.

WARNINGEWA13120


TIPPlace the vehicle on a maintenance stand sothat the rear wheel is elevated.

2. Remove:• Drive chain

TIPCut the drive chain with the drive chain cut & riv-et tool. (Use goods on the market.)

EAM30076

CHECKING THE DRIVE CHAIN1. Measure:

• 15-link section of the drive chainOut of specification Replace the drivechain.

a. Measure the length “a” between the innersides of the pins and the length “b” be-tween the outer sides of the pins on a 15-link section of the drive chain as shown inthe illustration.

b. Calculate the length “c” of the 15-link sec-tion of the drive chain using the followingformula.Drive chain 15-link section length “c” =(length “a” between pin inner sides +length “b” between pin outer sides)/2

TIP• When measuring a 15-link section of the drive

chain, make sure that the drive chain is taut.• Perform this procedure 2–3 times, at a different

location each time.

2. Check:• Drive chain

Stiffness Clean, lubricate, or replace.

3. Clean:• Drive chain

a. Wipe the drive chain with a clean cloth.b. Put the drive chain in kerosene and re-

move any remaining dirt.c. Remove the drive chain from the kerosene

and completely dry it.

NOTICEECA19090

• This vehicle has a drive chain with smallrubber O-rings “1” between the drive chainside plates. Never use high-pressure wateror air, steam, gasoline, certain solvents(e.g., benzine), or a coarse brush to cleanthe drive chain. High-pressure methodscould force dirt or water into the drivechain’s internals, and solvents will deterio-rate the O-rings. A coarse brush can alsodamage the O-rings. Therefore, use onlykerosene to clean the drive chain.

• Do not soak the drive chain in kerosene formore than ten minutes, otherwise the O-rings can be damaged.

15-link length limit239.3 mm (9.42 in)

G088937

G088938

G088939

CHAIN DRIVE

4-64

4. Check:• O-ring “1”

Damage Replace the drive chain.• Drive chain roller “2”

Damage/wear Replace the drive chain.• Drive chain side plate “3”

Damage/wear Replace the drive chain.

5. Lubricate:• Drive chain

EAM30077

CHECKING THE DRIVE SPROCKET1. Check:

• Drive sprocketMore than 1/4 tooth wear “a” Replace thedrive sprocket and the rear wheel sprocket asa set.Bent tooth Replace the drive sprocket andthe rear wheel sprocket as a set.

EAM30078

CHECKING THE REAR WHEEL SPROCKETRefer to “CHECKING AND REPLACING THEREAR WHEEL SPROCKET” on page 4-8.

EAM30079

INSTALLING THE DRIVE CHAIN1. Install:

• Drive chain

NOTICEECA17410

Be sure to put on safety goggles when work-ing.

TIPInstall the master link with the drive chain cut &rivet tool. (Use goods on the market.)

a. When press fitting the master link plate“1”, make sure the space “a” between theend of the connecting pin “2” and the mas-ter link plate is 1.2–1.4 mm (0.05–0.06 in).

b. After riveting, make sure the diameter be-tween the edges “b” of the connecting pin“2” is 5.5–5.8 mm (0.22–0.23 in).


G088940

G088941

G088943

b. Correct

1. Drive chain roller2. Drive sprocket

G088904

CHAIN DRIVE

4-65

c. After riveting, make sure the space “c”,which is inside of the master link “3” andinside of the master link plate “1”, is 12.1–12.3 mm (0.476–0.484 in).

2. Lubricate:• Drive chain

3. Install:• Drive sprocket• Lock washer • Drive sprocket nut

Refer to “ENGINE REMOVAL” on page 5-1.

NOTICEECA14300

Never install a new drive chain onto worndrive chain sprockets; this will dramaticallyshorten the drive chain’s life.

4. Adjust:• Drive chain slack

Refer to “DRIVE CHAIN SLACK” on page3-16.

NOTICEECA24590

A drive chain that is too tight will overloadthe engine and other vital parts, and one thatis too loose can skip and damage the swing-arm or cause an accident. Therefore, keepthe drive chain slack within the specified lim-its.


Drive sprocket nut75 N·m (7.5 kgf·m, 55 lb·ft)


48.0–58.0 mm (1.89–2.28 in)

New

TR..

CHAIN DRIVE

4-66

1

2

3

4

5

6

7

8

9

10

ENGINE

ENGINE REMOVAL ..........................................................................................5-1REMOVING THE ENGINE .........................................................................5-4INSTALLING THE ENGINE........................................................................5-4

CYLINDER HEAD, CYLINDER AND PISTON .................................................5-5REMOVING THE CYLINDER HEAD..........................................................5-7REMOVING THE PUSH ROD ....................................................................5-7REMOVING THE PISTON..........................................................................5-7CHECKING THE CYLINDER HEAD ..........................................................5-8CHECKING THE CYLINDER AND PISTON...............................................5-8COMBINATION OF PISTON AND CYLINDER ..........................................5-9CHECKING THE PISTON RING ..............................................................5-10CHECKING THE PISTON PIN .................................................................5-10CHECKING THE SMALL END BEARING ................................................5-11CHECKING THE POWER VALVE ...........................................................5-11CHECKING THE POWER VALVE HOLE ON CYLINDER .......................5-11ASSEMBLING THE POWER VALVE .......................................................5-11INSTALLING THE PISTON AND CYLINDER ..........................................5-12INSTALLING THE CYLINDER HEAD ......................................................5-14

CDI MAGNETO ...............................................................................................5-15REMOVING THE ROTOR ........................................................................5-16CHECKING THE CDI MAGNETO ............................................................5-16CHECKING THE WOODRUFF KEY ........................................................5-16INSTALLING THE CDI MAGNETO ..........................................................5-16

KICKSTARTER ...............................................................................................5-18REMOVING THE PRIMARY DRIVE GEAR .............................................5-20REMOVING THE KICK SHAFT ASSEMBLY ...........................................5-20CHECKING THE KICK GEAR AND KICK IDLE GEAR............................5-20INSTALLING THE KICK SHAFT ASSEMBLY ..........................................5-20INSTALLING THE KICK IDLE GEAR .......................................................5-21INSTALLING THE PRIMARY DRIVE GEAR ............................................5-21INSTALLING THE KICKSTARTER LEVER..............................................5-22

YPVS GOVERNOR .........................................................................................5-23REMOVING THE GOVERNOR ................................................................5-24CHECKING THE GOVERNOR GROOVE................................................5-24CHECKING THE BEARING .....................................................................5-24INSTALLING THE GOVERNOR...............................................................5-24

CLUTCH..........................................................................................................5-26REMOVING THE CLUTCH ......................................................................5-28CHECKING THE FRICTION PLATES......................................................5-28CHECKING THE CLUTCH PLATES ........................................................5-28CHECKING THE CLUTCH SPRINGS......................................................5-28CHECKING THE CLUTCH HOUSING .....................................................5-28

CHECKING THE CLUTCH BOSS ............................................................5-28CHECKING THE PRESSURE PLATE .....................................................5-29CHECKING THE PUSH LEVER SHAFT ..................................................5-29CHECKING THE PUSH RODS ................................................................5-29CHECKING THE PRIMARY DRIVE GEAR ..............................................5-29CHECKING THE PRIMARY DRIVEN GEAR............................................5-29INSTALLING THE CLUTCH .....................................................................5-29

SHIFT SHAFT .................................................................................................5-32REMOVING THE SEGMENT ...................................................................5-33CHECKING THE SHIFT SHAFT ..............................................................5-33CHECKING THE STOPPER LEVER........................................................5-33INSTALLING THE SHIFT SHAFT ............................................................5-33

CRANKCASE .................................................................................................5-36DISASSEMBLING THE CRANKCASE.....................................................5-37CHECKING THE CRANKCASE ...............................................................5-37ASSEMBLING THE CRANKCASE...........................................................5-37

CRANKSHAFT ...............................................................................................5-40REMOVING THE CRANKSHAFT.............................................................5-41CHECKING THE CRANKSHAFT .............................................................5-41INSTALLING THE CRANKSHAFT ...........................................................5-41

TRANSMISSION.............................................................................................5-43REMOVING THE TRANSMISSION..........................................................5-44CHECKING THE SHIFT FORKS..............................................................5-44CHECKING THE SHIFT DRUM ASSEMBLY ...........................................5-44CHECKING THE TRANSMISSION ..........................................................5-44INSTALLING THE TRANSMISSION ........................................................5-45

ENGINE REMOVAL

5-1

EAM20105

ENGINE REMOVALRemoving the exhaust pipe


Right side cover Refer to “GENERAL CHASSIS” on page 4-1.

1 Washer 1 [ø = 26 mm (1.02 in)]

2 Washer 1 [ø = 22 mm (0.87 in)]

3 Silencer 14 Collar 1 [L = 15.5 mm (0.61 in)]

5 Collar 1 [L = 13.5 mm (0.53 in)]

6 Grommet (front) 17 Grommet (rear) 1

8 Tension spring 2

9 Exhaust pipe 1

1

2

3

4

5

6

7

8

9

12 N・m (1.2 kgf・m, 8.9 lb・ft)

12 N・m (1.2 kgf・m, 8.9 lb・ft)

12 N・m (1.2 kgf・m, 8.9 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

12 N・m (1.2 kgf・m, 8.9 lb・ft)

15 mm(0.59 in)

17 mm(0.67 in)

ENGINE REMOVAL

5-2

Removing the engine


Transmission oilDrain.Refer to “CHANGING THE TRANSMISSION OIL” on page 3-6.


Fuel tank Refer to “FUEL TANK” on page 7-1.Carburetor Refer to “CARBURETOR” on page 7-3.

Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 5-1.

Exhaust pipe stay (rear) Refer to “ENGINE REMOVAL” on page 5-1.Clutch cable Disconnect at engine side.

Radiator Refer to “RADIATOR” on page 6-2.

Spark plugCDI magneto lead Disconnect.

1 Drive chain sprocket cover 1

2 Drive chain sprocket guide 13 Lock washer 1

4 Drive sprocket 1

5 Brake pedal 16 Spring 1

7 Engine bracket 2

8 Pivot shaft 1

34 N・m (3.4 kgf・m, 25 lb・ft)

1

3

4

5

7

5 N・m (0.5 kgf・m, 3.7 lb・ft)

64 N・m (6.4 kgf・m, 47 lb・ft)

75 N・m (7.5 kgf・m, 55 lb・ft)

85 N・m (8.5 kgf・m, 63 lb・ft)

26 N・m (2.6 kgf・m, 19 lb・ft)

7

2

6

8

ENGINE REMOVAL

5-3

Removing the engine


9 Engine 1

34 N・m (3.4 kgf・m, 25 lb・ft)

9

5 N・m (0.5 kgf・m, 3.7 lb・ft)

64 N・m (6.4 kgf・m, 47 lb・ft)

75 N・m (7.5 kgf・m, 55 lb・ft)

85 N・m (8.5 kgf・m, 63 lb・ft)

26 N・m (2.6 kgf・m, 19 lb・ft)

ENGINE REMOVAL

5-4

EAM30161

REMOVING THE ENGINE1. Remove:

• Pivot shaft “1”TIPIf the pivot shaft is pulled all the way out, theswingarm will come loose. If possible, insert ashaft of similar diameter into the other side of theswingarm to support it.

2. Remove:• Engine “1”

(from right side)TIPMake sure that the couplers, hoses and cablesare disconnected.

EAM30164

INSTALLING THE ENGINE1. Install:

• Engine “1”Install the engine from right side.

• Pivot shaft “2”• Pivot shaft nut “3”

• Engine mounting bolt (lower side) “4”• Engine mounting nut (lower side) “5”

• Engine mounting bolt (front side) “6”

• Engine mounting nut (front side) “7”

• Engine bracket “8”• Engine bracket bolt (upper side) “9”• Engine bracket nut (upper side) “10”

• Engine bracket bolt (lower side) “11”• Engine bracket nut (lower side) “12”

TIPApply the molybdenum disulfide grease on thepivot shaft.

Pivot shaft nut85 N·m (8.5 kgf·m, 63 lb·ft)

Engine mounting nut (lower side)64 N·m (6.4 kgf·m, 47 lb·ft)

TR..

TR..

Engine mounting nut (front side)64 N·m (6.4 kgf·m, 47 lb·ft)

Engine bracket nut (upper side)34 N·m (3.4 kgf·m, 25 lb·ft)

Engine bracket nut (lower side)34 N·m (3.4 kgf·m, 25 lb·ft)

TR..

TR..

TR..

CYLINDER HEAD, CYLINDER AND PISTON

5-5

EAM20190

CYLINDER HEAD, CYLINDER AND PISTONRemoving the cylinder head and cylinder



Fuel tank Refer to “FUEL TANK” on page 7-1.

Exhaust pipe and silencer Refer to “ENGINE REMOVAL” on page 5-1.

Radiator hose 1 Disconnect at cylinder head side.Carburetor Refer to “CARBURETOR” on page 7-3.

1 Spark plug 1

2 Engine bracket 23 Cylinder head 1

4 Power valve housing 1

5 Push rod 16 Cylinder 1

1

2

3

4

5 (4)

(5)

6

13 N・m (1.3 kgf・m, 9.6 lb・ft)

20 N・m (2.0 kgf・m, 15 lb・ft)

34 N・m (3.4 kgf・m, 25 lb・ft)

28 N・m (2.8 kgf・m, 21 lb・ft)

4.5 N・m (0.45 kgf・m, 3.3 lb・ft)

4.0 N・m (0.40 kgf・m, 3.0 lb・ft)

30 N・m (3.0 kgf・m, 22 lb・ft)


5-6

Disassembling the YPVS system


1 Piston pin clip 2

2 Piston pin 1

3 Piston 14 Small end bearing 1

5 Piston ring 1

6 Power valve cover 17 Thrust plate 1

8 Power valve holder 1

9 Valve shaft 110 Collar 2

11 Link lever 1

12 Power valve 1 113 Power valve 2 1

12

3

4

5

1

6

7

8

9

1011

12

13

4.0 N・m (0.40 kgf・m, 3.0 lb・ft)

8 N・m (0.8 kgf・m, 5.9 lb・ft)

4.0 N・m (0.40 kgf・m, 3.0 lb・ft)

5 N・m (0.5 kgf・m, 3.7 lb・ft)

10


5-7

EAM30086

REMOVING THE CYLINDER HEAD1. Remove:

• Cylinder head nutTIPLoosen each nut 1/2 of a turn at a time. After allof the nuts are fully loosened, remove them.

EAM30543

REMOVING THE PUSH ROD1. Remove:

• Push rod bolt “1”• Push rod “2”

NOTICEECA26450


TIP• Set the collar “3” included in owner’s tool kit to

remove the push rod bolt.• Do not forget to remove the collar.

2. Remove:• Collar

EAM30544

REMOVING THE PISTON1. Remove:

• Piston pin clip “1”TIPBefore removing the piston pin clip, cover thecrankcase opening with a clean rag to preventthe piston pin clip from falling into the crankcase.

2. Remove:• Piston pin “1”• Piston “2”• Small end bearing

NOTICEECA13810

Do not use a hammer to drive the piston pinout.

TIPBefore removing the piston pin, deburr the pis-ton pin clip’s groove and the piston’s pin bore ar-ea. If both areas are deburred and the piston pinis still difficult to remove, remove it with the pis-ton pin puller set “3”.

3. Remove:• Piston ring

TIPWhen removing a piston ring, open the end gapwith your fingers and lift the other side of the ringover the piston crown.

Piston pin puller set90890-01304

Piston pin pullerYU-01304

1

1

3

2

G088998


5-8

EAM30545

CHECKING THE CYLINDER HEAD1. Eliminate:

• Combustion chamber carbon deposits (with arounded scraper “1”)

TIPDo not use a sharp instrument to avoid damag-ing or scratching:• Spark plug bore threads

2. Check:• Cylinder head

Damage/scratches Replace.• Cylinder head water jacket

Mineral deposits/rust Eliminate.3. Measure:

• Cylinder head warpageOut of specification Resurface the cylinderhead.

a. Place a straightedge “1” and a thicknessgauge “2” across the cylinder head.

b. Measure the warpage.c. If the limit is exceeded, resurface the cylin-

der head as follows.d. Place a 400–600 grit wet sandpaper on

the surface plate and resurface the cylin-der head using a figure-eight sanding pat-tern.

TIPTo ensure an even surface, rotate the cylinderhead several times.

EAM30546

CHECKING THE CYLINDER AND PISTON1. Check:

• Piston wall• Cylinder wall

Vertical scratches Replace the cylinder,and replace the piston and piston rings as aset.

2. Measure:• Piston-to-cylinder clearance

a. Measure the cylinder bore “C” with the cyl-inder bore gauge.

TIPMeasure the cylinder bore “C” by taking side-to-side and front-to-back measurements of the cyl-inder.

b. If out of specification, replace the cylinder,and replace the piston and piston rings asa set.

c. Measure the piston skirt diameter with themicrometer.

d. Measure the specific distance “a” from thebottom edge of the piston.

Warpage limit0.03 mm (0.0012 in)

G088999

1

1

2

Bore54.000–54.014 mm (2.1260–2.1265 in)

Wear limit54.064 mm (2.1285 in)

“C” = maximum of D1, D2, D3, D4, D5, D6

G089000


5-9

e. If out of specification, replace the pistonand piston rings as a set.

f. Calculate the piston-to-cylinder clearancewith the following formula.

g. If out of specification, replace the cylinder,and replace the piston and piston rings asa set.

EAM30547

COMBINATION OF PISTON AND CYLINDER1. Check:

• Cylinder mark “a”

2. Check:• Piston mark “a”

3. Combination:• Combine the piston and cylinder by the fol-

lowing chart.

TIPWhen you purchase a cylinder, you cannot des-ignate its size. Choose the piston that matchesthe above chart.

Diameter53.957–53.972 mm (2.1243–2.1249 in)

a. 17.5 mm (0.69 in) from the bottom edge of the piston

Piston-to-cylinder clearance =Cylinder bore - Piston skirt diameter

Piston-to-cylinder clearance0.040–0.045 mm (0.0016–0.0018 in)

Cylinder mark “a” Cylinder size

A 54.000–54.002 mm(2.1260–2.1261 in)

B 54.004–54.006 mm(2.1261–2.1262 in)

C 54.008–54.010 mm(2.1263–2.1264 in)

D 54.012–54.014 mm(2.1265–2.1265 in)

a

Piston mark “a” (color) Piston size

A (red) 53.957–53.960 mm(2.1243–2.1244 in)

B (orange) 53.961–53.964 mm(2.1244–2.1246 in)

C (green) 53.965–53.968 mm(2.1246–2.1247 in)

D (purple) 53.969–53.972 mm(2.1248–2.1249 in)

Cylinder mark Piston mark (color)

A A (red)

B B (orange)

C C (green)

D D (purple)


5-10

EAM30548

CHECKING THE PISTON RING1. Measure:

• Piston ring side clearanceOut of specification Replace the pistonand piston ring as a set.

TIPBefore measuring the piston ring side clearance,eliminate any carbon deposits from the pistonring grooves and piston ring.

2. Install:• Piston ring

(into the cylinder)TIPUse the piston crown to level the piston ring nearbottom of cylinder “a”, where cylinder wear islowest.

3. Measure:• Piston ring end gap

Out of specification Replace the pistonring.

EAM30549

CHECKING THE PISTON PIN1. Check:

• Piston pinBlue discoloration/grooves Replace thepiston pin, and then check the fuel and en-gine mixing oil.

2. Measure:• Piston pin outside diameter “a”

Out of specification Replace the piston pin.

3. Measure:• Piston pin bore inside diameter “b”

Out of specification Replace the piston.

4. Calculate:• Piston-pin-to-piston-pin-bore clearance

Out of specification Replace the piston pinand piston as a set.

Top ringRing side clearance

0.035–0.070 mm (0.0014–0.0028 in)

Side clearance limit0.100 mm (0.0039 in)

End gap limit1.20 mm (0.0472 in)

b. Upper of cylinder

G089002

a

b

G089003

Piston pin outside diameter limit14.975 mm (0.5896 in)

Piston pin bore inside diameter limit

15.040 mm (0.5921 in)

Piston-pin-to-piston-pin-bore clearance =Piston pin bore inside diameter “b” -Piston pin outside diameter “a”

G089004

bG089005


5-11

EAM30550

CHECKING THE SMALL END BEARING1. Check:

• Small end bearingSigns of heat discoloration Replace.

EAM30553

CHECKING THE POWER VALVE1. Check:

• Power valve 1, 2 “1”Wear/damage Replace.Carbon deposits Remove.

• Power valve holder “2”• Link lever “3”• Valve shaft “4”• Collar “5”

Wear/damage Replace.• Spring “6”

Broken Replace.

EAM30552

CHECKING THE POWER VALVE HOLE ON CYLINDER1. Remove:

• Carbon deposits(from power valve hole surface “a”)

TIPDo not use a sharp instrument. Avoid scratching

the aluminum.

EAM30551

ASSEMBLING THE POWER VALVE1. Install:

• Power valve 1 “1”• Power valve 2 “2”• Bolt (power valve) “3”

TIPInstall the power valve at cut-away faced “a” fordown side.

2. Install:• Spring “1”• Link lever “2”• Collar “3”• Valve shaft “4”• Power valve holder “5”• Power valve link lever bolt “6”

TIP• Install the spring to the link lever, and then to

the cylinder.• Install the spring with its stopper portion “a” fac-

ing inward.• Apply the lithium soap base grease on the oil

seal lip.

Piston-pin-to-piston-pin-bore clearance

0.008–0.023 mm (0.0003–0.0009 in)

Limit0.065 mm (0.0026 in)

Bolt (power valve)8 N·m (0.8 kgf·m, 5.9 lb·ft)

Power valve link lever bolt4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

TR..

a

3

2

13

TR..


5-12

3. Install:• Thrust plate “1”• Thrust plate screw “2”

4. Check:• Power valve smooth movement

Unsmooth movement Repair or replace.

5. Install:• Gasket (power valve cover) “1” • Power valve cover “2”• Power valve cover screw “3”

• YPVS breather hose “4”TIP• Install the power valve cover so that the arrow

mark “a” faces upward.• Install the clamp of the YPVS breather hose

with its opening portion “b” facing backward.

EAM30554

INSTALLING THE PISTON AND CYLINDER1. Install:

• Piston ring “1”TIP• Take care not to scratch the piston or damage

the piston ring.• Align the piston ring gap with the pin “2”.• After installing the piston ring, check the

smooth movement of it.

2. Install:• Cylinder gasket “1” • Small end bearing “2”

(with the recommended lubricant)• Dowel pin “3”

Thrust plate screw4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

Power valve cover screw5 N·m (0.5 kgf·m, 3.7 lb·ft)

4 1

1

1

5 1

6

32

2

a

3

TR..

New

TR..

Recommended lubricantEngine oil

New


5-13

3. Install:• Piston “1”• Piston pin “2”• Piston pin clip “3”

TIP• Apply engine oil the piston pin.• Make sure the arrow mark “a” on the piston

points towards the exhaust side of the cylinder.• Before installing the piston pin clip, cover the

crankcase opening with a clean rag to preventthe clip from falling into the crankcase.

• Do not allow the clip open ends to meet the pis-ton pin slit “b”.

4. Lubricate:• Piston• Piston ring• Cylinder

(with the recommended lubricant)

5. Install:• Cylinder• Cylinder nut “1”

TIP• While compressing the piston ring with one

hand, install the cylinder with the other hand.• Tighten the nuts in stage, using a crisscross

pattern.

6. Install:• Collar “1”• Push rod “2”• Plain washer “3”• Push rod bolt “4”

NOTICEECA27100


TIP• Insert the collar “5” included in owner’s tool kit

to install the push rod bolt.• Do not forget to remove the collar.

Recommended lubricantEngine oil

New

Cylinder nut30 N·m (3.0 kgf·m, 22 lb·ft)

Push rod bolt4.5 N·m (0.45 kgf·m, 3.3 lb·ft)

TR..

TR..


5-14

7. Remove:• Collar

8. Install:• Gasket (power valve housing) • Power valve housing “1”• Power valve housing bolt “2”

EAM30555

INSTALLING THE CYLINDER HEAD1. Lubricate:

• O-ring

2. Install:• O-ring “1” • Dowel pin

TIPApply the lithium soap base grease on the O-rings.

3. Install:• Cylinder head “1”• Copper washer “2” • Cylinder head nut “3”

TIPTighten the cylinder head nut in stage, using acrisscross pattern.

4. Install:• Spark plug• Spark plug cap• Radiator hose

Power valve housing bolt4.0 N·m (0.40 kgf·m, 3.0 lb·ft)


New

TR..

New

Cylinder head nut28 N·m (2.8 kgf·m, 21 lb·ft)

Spark plug20 N·m (2.0 kgf·m, 15 lb·ft)

1

New

TR..

TR..

CDI MAGNETO

5-15

EAM20191

CDI MAGNETORemoving the CDI magneto




Radiator bolt Refer to “RADIATOR” on page 6-2.

CDI magneto lead Disconnect.1 Crankcase cover (left) 1

2 Rotor nut 1

3 CDI magneto rotor 14 Stator 1

5 Woodruff key 1

7 N・m (0.7 kgf・m, 5.2 lb・ft)

56 N・m (5.6 kgf・m, 41 lb・ft)

5 N・m (0.5 kgf・m, 3.7 lb・ft)

1

2

3

45

CDI MAGNETO

5-16

EAM30562

REMOVING THE ROTOR1. Remove:

• Rotor nut “1”• Washer “2”

TIPWhile holding the rotor with the rotor holding tool“3”, loosen the rotor nut.

2. Remove:• Rotor “1”

(with the flywheel puller “2”) • Woodruff key

TIPWhen installing the flywheel puller, turn it coun-terclockwise.

EAM30563

CHECKING THE CDI MAGNETO1. Check:

• Rotor inner surface “a”• Stator outer surface “b”

Damage Inspect the crankshaft runout andcrankshaft bearing.If necessary, replace CDI magneto and/orstator.

EAM30564

CHECKING THE WOODRUFF KEY1. Check:

• Woodruff key “1”Damage Replace.

EAM30565

INSTALLING THE CDI MAGNETO1. Install:

• Stator “1”• Stator coil screw “2”

TIPTemporarily tighten the screw at this point.

2. Install:• Woodruff key “1”• Rotor “2”

TIP• Clean the tapered portions of the crankshaft

Rotor holding tool90890-01235

Universal magneto and rotor holder

YU-01235

Flywheel puller90890-01189

Flywheel pullerYM-01189

CDI MAGNETO

5-17

and rotor.• When installing the woodruff key, make sure

that its flat surface “a” is in parallel with thecrankshaft center line “b”.

• When installing the rotor, align the keyway “c”of the rotor with the woodruff key.

3. Install:• Washer “1”• Rotor nut “2”

(with the rotor holding tool “3”)

4. Adjust:• Ignition timing

Refer to “CHECKING THE IGNITION TIM-ING” on page 3-26.

5. Tighten:• Stator coil screw “1”

6. Check:• Ignition timing

Re-check the ignition timing.7. Connect:

• CDI magneto lead “1”Refer to “CABLE ROUTING DIAGRAM” onpage 2-15.

8. Install:• Crankcase cover gasket (left) • Crankcase cover (left) “1”• Crankcase cover screw (left) “2”

TIPTighten the screws in stage, using a crisscrosspattern.

CDI magneto rotor nut56 N·m (5.6 kgf·m, 41 lb·ft)

Rotor holding tool90890-01235

Universal magneto and rotor holder

YU-01235

Stator coil screw7 N·m (0.7 kgf·m, 5.2 lb·ft)

TR..

TR..

Crankcase cover screw (left)5 N·m (0.5 kgf·m, 3.7 lb·ft)

New

TR..

KICKSTARTER

5-18

EAM20112

KICKSTARTERRemoving the primary drive gear



Bolt (brake pedal) Shift the brake pedal downward.

Radiator hose 4 Disconnect at water pump side.

Push rod bolt Refer to “CYLINDER HEAD, CYLINDER AND PISTON” on page 5-5.

1 Kickstarter lever 1

2 Crankcase cover (right) 1

3 Bolt (primary drive gear) 14 Primary driven gear 1

5 Primary drive gear 1

1

2

3

4

5

10 N・m (1.0 kgf・m, 7.4 lb・ft)

48 N・m (4.8 kgf・m, 35 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

KICKSTARTER

5-19

Removing the kickstarter shaft


1 Kick idle gear 1

2 Kick shaft assembly 1

1

2

KICKSTARTER

5-20

EAM30570

REMOVING THE PRIMARY DRIVE GEAR1. Loosen:

• Primary drive gear bolt “1”TIPPlace an aluminum plate “a” between the teethof the primary drive gear “2” and driven gear “3”.

EAM30101

REMOVING THE KICK SHAFT ASSEMBLY1. Remove:

• Kick shaft assembly “1”TIPUnhook the torsion spring “2” from the hole “a” inthe crankcase.

EAM30616

CHECKING THE KICK GEAR AND KICK IDLE GEAR1. Check:

• Kick gear “1”Wear/damage Replace the kick shaft as-sembly.

• Kick idle gear “2”• Gear teeth “a”


EAM30104

INSTALLING THE KICK SHAFT ASSEMBLY1. Install:

• Kick gear “1”• Washer “2”• Torsion spring “3”

(to kick shaft “4”)TIPMake sure the stopper “a” of the torsion springfits into the hole “b” on the kick shaft.

2. Install:• Spring guide “1”

TIPSlide the spring guide into the kick shaft, makesure the groove “a” in the spring guide fits on thestopper of the torsion spring.

3. Install:• Kick shaft assembly “1”

TIP• Apply the transmission oil on the kick shaft.

KICKSTARTER

5-21

• Slide the kick shaft assembly into the crank-case, make sure the clip “2” and kick shaftstopper “a” fit into their home position “b”, “c”.

4. Hook:• Torsion spring “1”

TIPTurn the torsion spring clockwise and hook intothe proper hole “a” in the crankcase.

EAM30105

INSTALLING THE KICK IDLE GEAR1. Install:

• Kick idle gear “1”• Washer “2”• Circlip “3”

TIPApply the transmission oil on the kick idle gearinner circumference.

EAM30571

INSTALLING THE PRIMARY DRIVE GEAR1. Install:

• Spacer “1”

• Primary drive gear “2”• Primary drive gear bolt “3”

TIPInstall the primary drive gear with its depressedside toward you.

2. Install:• Primary driven gear

Refer to “CLUTCH” on page 5-26.3. Tighten:

• Primary drive gear bolt “1”

TIPPlace an aluminum plate “a” between the teethof the primary drive gear and driven gear.

4. Install:• Dowel pin “1”• Gasket (crankcase cover (right)) “2”

New

Primary drive gear bolt48 N·m (4.8 kgf·m, 35 lb·ft)T

R..

New

KICKSTARTER

5-22

5. Install:• Crankcase cover (right) “1”

TIPMesh the governor gear “2”, and impeller shaftgear “3” with primary drive gear “4”.

6. Install:• Crankcase cover screw (right) “1”

TIPTighten the screws in stage, using a crisscrosspattern.

EAM30572

INSTALLING THE KICKSTARTER LEVER1. Install:

• Kickstarter lever “1”• Washer “2”• Kickstarter lever bolt “3”

TIPInstall the kickstarter closest to but not contact-ing the pillar tube “4”.

2. Install:• Shift pedal “1”• Shift pedal bolt “2”

TIPAlign the upper line “a” of the shift pedal with thecenter “b” of the crankcase projection and rotatethe shift pedal counterclockwise until it first en-gages. Then install the shift pedal.

Crankcase cover screw (right)10 N·m (1.0 kgf·m, 7.4 lb·ft)

Kickstarter lever10 N·m (1.0 kgf·m, 7.4 lb·ft)

TR..

TR..

Shift pedal bolt12 N·m (1.2 kgf·m, 8.9 lb·ft)T

R..

YPVS GOVERNOR

5-23

EAM20192

YPVS GOVERNORRemoving the YPVS governor


Crankcase cover (right) Refer to “KICKSTARTER” on page 5-18.

1 Governor assembly 1

2 Dowel pin 13 Retainer 1

4 Ball 4

5 Retainer weight 16 Washer 3

7 Bearing 2

8 Collar 19 Plate 1

10 Compression spring 1

11 Governor gear 112 Governor shaft 1

13 Governor fork 1

1

2

3

45

67

8

910

11

12

5 N・m (0.5 kgf・m, 3.7 lb・ft)

6

76

13

YPVS GOVERNOR

5-24

EAM30566

REMOVING THE GOVERNOR1. Remove:

• Dowel pin “1”TIPWhile compressing the spring, remove the dow-el pin.

EAM30567

CHECKING THE GOVERNOR GROOVE1. Check:

• Washer “1”• Collar “2”


EAM30568

CHECKING THE BEARING1. Check:

• Thrust bearing “1”• Washer “2”


EAM30569

INSTALLING THE GOVERNOR1. Install:

• Governor gear “1”• Compression spring “2”• Plate “3”• Washer “4”• Thrust bearing “5”• Collar “6”• Retainer weight “7”

(to governor shaft “8”)TIPApply the lithium soap base grease on the thrustbearing.

2. Install:• Ball “1”• Retainer “2”

(to governor shaft “3”)TIPApply the transmission oil on the retainer andball.

1

1

2

1 22


3

44

4

5

5

6

7

1

2

8

YPVS GOVERNOR

5-25

3. Install:• Dowel pin “1”

TIP• While compressing the spring, install the dowel

pin.• Make sure the dowel pin fits into the groove “a”

in the retainer.

4. Install:• Governor assembly “1”

TIPAlign the groove “a” in the governor with the fork“b” and set the governor in the crankcase cover.

G

1 2

3

1

a

CLUTCH

5-26

EAM20111

CLUTCHRemoving the clutch



Bolt (brake pedal) Shift the brake pedal downward.

Rotor and stator Refer to “CDI MAGNETO” on page 5-15.

Clutch cable Disconnect at engine side.1 Clutch cover 1

2 Gasket 1

3 Clutch spring 54 Pressure plate 1

5 Friction plate 8

6 Clutch plate 7

1

2

(5)

3

4

56

10 N・m (1.0 kgf・m, 7.4 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

CLUTCH

5-27

Removing the clutch boss


1 Push rod 1 1

2 Circlip 1

3 Washer 14 Bearing 1

5 Ball 1

6 Push rod 2 17 Clutch boss nut 1

8 Lock washer 1

9 Clutch boss 110 Thrust washer 1 [D = ø34 mm (1.34 in)]

11 Primary driven gear 1

12 Bearing 113 Spacer 1 1

14 Thrust washer 1 [D = ø34 mm (1.34 in)]

15 Push lever shaft 1

1

23

4

5

6

78

9

10

11 12

14

15

80 N・m (8.0 kgf・m, 59 lb・ft)

13

CLUTCH

5-28

EAM30108

REMOVING THE CLUTCH1. Remove:

• Clutch boss nut “1”• Lock washer• Clutch boss “2”

TIP• While holding the clutch boss with the univer-

sal clutch holder “3”, loosen the clutch bossnut.

• Do not use an impact wrench for removing theclutch boss nut.

EAM30109

CHECKING THE FRICTION PLATES1. Check:

• Friction plateDamage/wear Replace the friction platesas a set.

2. Measure:• Friction plate thickness

Out of specification Replace the frictionplates as a set.

TIPMeasure it at four points on the friction plate.

EAM30110

CHECKING THE CLUTCH PLATES1. Check:

• Clutch plateDamage Replace the clutch plates as aset.

2. Measure:• Clutch plate warpage

(with a surface plate and thickness gauge)Out of specification Replace the clutchplates as a set.

EAM30111

CHECKING THE CLUTCH SPRINGS1. Check:

• Clutch springDamage Replace the clutch springs as aset.

2. Measure:• Clutch spring free length

Out of specification Replace the clutchsprings as a set.

EAM30112

CHECKING THE CLUTCH HOUSING1. Check:

• Clutch housing dogsDamage/pitting/wear Deburr the clutchhousing dogs or replace the clutch housing.

TIPPitting on the clutch housing dogs will cause er-ratic clutch operation.

EAM30113

CHECKING THE CLUTCH BOSS1. Check:

• Clutch boss splinesDamage/pitting/wear Replace the clutch

Universal clutch holder90890-04086

Universal clutch holderYM-91042

Friction plate thickness2.90–3.10 mm (0.114–0.122 in)

Wear limit2.80 mm (0.110 in)

1

2

3

G088993

Thickness gauge90890-03268

Feeler gauge setYU-26900-9

Clutch plate thickness1.50–1.70 mm (0.059–0.067 in)

Warpage limit0.20 mm (0.008 in)

Clutch spring free length40.10 mm (1.58 in)

Clutch spring free length limit38.10 mm (1.50 in)

G088994

CLUTCH

5-29

boss.TIPPitting on the clutch boss splines will cause er-ratic clutch operation.

EAM30114

CHECKING THE PRESSURE PLATE1. Check:

• Pressure plateCrack/damage Replace.

EAM30115

CHECKING THE PUSH LEVER SHAFT1. Check:

• Push lever shaft “1”Wear/damage Replace.

EAM30484

CHECKING THE PUSH RODS1. Check:

• Push rod 1 “1”• Bearing “2”• Washer “3”• Push rod 2 “4”• Ball “5”

Cracks/damage/wear Replace.

2. Measure:• Push rod 2 bending limit

Out of specification Replace.

EAM30117

CHECKING THE PRIMARY DRIVE GEAR1. Check:

• Primary drive gearDamage/wear Replace the primary driveand primary driven gears as a set.Excessive noise during operation Replacethe primary drive and primary driven gears asa set.

2. Check:• Primary-drive-gear-to-primary-driven-gear

free playFree play exists Replace the primary driveand primary driven gears as a set.

EAM30118

CHECKING THE PRIMARY DRIVEN GEAR1. Check:

• Primary driven gearDamage/wear Replace the primary driveand primary driven gears as a set.Excessive noise during operation Replacethe primary drive and primary driven gears asa set.

EAM30121

INSTALLING THE CLUTCH1. Install:

• Push lever shaft “1”TIPApply the lithium-soap-based grease on the oilseal lip.

G088995

Push rod bending limit0.30 mm (0.012 in)

CLUTCH

5-30

2. Install:• Thrust washer [D = ø34 mm (1.34 in)] “1”• Spacer “2”• Bearing “3”• Primary driven gear “4”

TIPApply the transmission oil on the bearing, spacerand primary driven gear inner circumference.

3. Install:• Thrust washer [D = ø34 mm (1.34 in)] “1”• Clutch boss “2”

4. Install:• Lock washer “1” • Clutch boss nut “2”

TIPUse the universal clutch holder “3” to hold theclutch boss.

5. Bend the lock washer “1” tab.

6. Install:• Friction plate “1”• Clutch plate “2”

TIP• Install the clutch plates and friction plates alter-

nately on the clutch boss, starting with a frictionplate and ending with a friction plate.

• Apply the transmission oil on the friction platesand clutch plates.

7. Install:• Bearing “1”• Washer “2”• Circlip “3”

(to push rod 1 “4”)

Clutch boss nut80 N·m (8.0 kgf·m, 59 lb·ft)

1

New

TR..

Universal clutch holder90890-04086

Universal clutch holderYM-91042

New

CLUTCH

5-31

TIPApply the transmission oil on the bearing, wash-er and push rod 1.

8. Install:• Push rod 2 “1”• Ball “2”• Push rod 1 “3”

TIPApply the transmission oil on the push rod 1, 2and ball.

9. Install:• Pressure plate “1”

10.Install:• Clutch spring• Clutch spring bolt

TIPTighten the bolts in stage, using a crisscross pat-

tern.

11.Install:• Dowel pin “1”• Gasket (clutch cover) “2”

12.Install:• Clutch cover• Clutch cover bolt

TIPTighten the bolts in stage, using a crisscross pat-tern.

13.Install:• O-ring “1” • Clutch cable “2”

TIPApply the lithium soap base grease on the O-ring.

Clutch spring bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)

G

32

1

4

TR..

Clutch cover bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)

New

TR..

New

1

2

SHIFT SHAFT

5-32

EAM20113

SHIFT SHAFTRemoving the shift shaft and stopper lever


1 Shift pedal 12 Shift shaft 1

3 Segment bolt 1

4 Roller 15 Shift guide 1

6 Shift lever assembly 1

7 Stopper lever 1

1

2

4

5

3

6

7

10 N・m (1.0 kgf・m, 7.4 lb・ft)

30 N・m (3.0 kgf・m, 22 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

12 N・m (1.2 kgf・m, 8.9 lb・ft)

SHIFT SHAFT

5-33

EAM30124

REMOVING THE SEGMENT1. Remove:

• Segment bolt “1”• Segment “2”

TIPTurn the segment counterclockwise until it stopsand loosen the bolt.

NOTICEECA24670

If the segment gets an impact, the stopper le-ver may be damaged. Take care not to givean impact to it when removing the bolt.

EAM30125

CHECKING THE SHIFT SHAFT1. Check:

• Shift shaft “1”Bends/damage/wear Replace.

• Shift shaft spring “2”Damage/wear Replace.

2. Check:• Shift guide “1”• Shift lever “2”• Pawl “3”• Pawl pin “4”• Spring “5”


EAM30127

CHECKING THE STOPPER LEVER1. Check:

• Stopper lever “1”Wear/damage Replace.

• Roller “2”Rotate outer race with a finger.Rough spot/seizure Replace the stopperlever.

• Torsion spring “3”Broken Replace.

EAM30131

INSTALLING THE SHIFT SHAFT1. Install:

• Torsion spring “1”• Holder “2”• Holder bolt “3”

• Washer “4”• Stopper lever “5”• Stopper lever bolt “6”

TIPAlign the stopper lever roller with the slot on seg-ment.

Holder bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)LOCTITE®

Stopper lever bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)LOCTITE®

TR..

TR..

SHIFT SHAFT

5-34

2. Install:• Segment “1”• Segment bolt

TIP• Align the notch “a” on the segment with the pin

“b” on the shift cam.• With the stopper lever pushed down, install the

segment.

NOTICEECA24680

If the segment gets an impact, the stopper le-ver may be damaged. Take care not to givean impact to it when tightening the bolt.

3. Install:• Spring “1”• Pawl pin “2”• Pawl “3”

(to the shift lever)TIPApply the transmission oil on the spring, pawl pinand pawl.

4. Install:• Shift lever assembly

(to the shift guide)5. Install:

• Shift lever assembly “1”• Shift guide “2”

TIP• The shift lever assembly is installed at the

same time as the shift guide.• Apply the transmission oil on the segment bolt

shaft.

6. Tighten:• Shift guide bolt “1”

7. Install:• Roller “1”• Shift shaft “2”

Segment30 N·m (3.0 kgf·m, 22 lb·ft)

LT2

13

4

5 6

LT

TR..

Shift guide bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)LOCTITE®

11

2233

G

TR..

LT

1

SHIFT SHAFT

5-35

TIPApply the transmission oil on the roller and shiftshaft.

8. Install:• Shift pedal “1”• Shift pedal bolt “2”

TIPAlign the upper line “a” of the shift pedal with thecenter “b” of the crankcase projection and rotatethe shift pedal counterclockwise until it first en-gages. Then install the shift pedal.

Shift pedal bolt12 N·m (1.2 kgf·m, 8.9 lb·ft)T

R..

CRANKCASE

5-36

EAM20116

CRANKCASESeparating the crankcase


Engine Refer to “ENGINE REMOVAL” on page 5-1.

Piston Refer to “CYLINDER HEAD, CYLINDER AND PISTON” on page 5-5.

Primary drive gear/kick idle gear Refer to “KICKSTARTER” on page 5-18.

Stopper lever Refer to “SHIFT SHAFT” on page 5-32.Rotor and stator Refer to “CDI MAGNETO” on page 5-15.

1 Segment 1

2 Crankcase bolt 6 [L = 45 mm (1.77 in)]3 Crankcase bolt 4 [L = 55 mm (2.17 in)]

4 Crankcase bolt 1 [L = 65 mm (2.56 in)]

5 Crankcase bolt 1 [L = 75 mm (2.95 in)]6 Holder 1

7 Crankcase (right) 1

8 Crankcase (left) 19 Oil seal 2

10 Bearing 2

1 6

7

8

9

10

2

3

4

5

3 3

3

2

2

2 2 2

10

9

10 N・m (1.0 kgf・m, 7.4 lb・ft) 30 N・m (3.0 kgf・m, 22 lb・ft) 14 N・m (1.4 kgf・m, 10 lb・ft)

20 N・m (2.0 kgf・m, 15 lb・ft)

CRANKCASE

5-37

EAM30147

DISASSEMBLING THE CRANKCASE1. Remove:

• Crankcase (right) “1”(with the crankcase separating tool “2”)

TIP• Make appropriate bolts “3” as shown available

by yourself and attach the tool with them.• Fully tighten the tool holding bolts, but make

sure the tool body is parallel with the case. Ifnecessary, one screw may be backed outslightly to level tool body.

• As pressure is applied, alternately tap on theengine mounting boss and transmissionshafts.

NOTICEECA24690

Use soft hammer to tap on the case half. Taponly on reinforced portions of case. Do nottap on gasket mating surface. Work slowlyand carefully. Make sure the case halvesseparate evenly. If the cases do not separate,check for a remaining case bolt or fitting. Donot force.

2. Remove:• Bearing “1”

TIP• Remove the bearing from the crankcase by

pressing its inner race.• Do not use the removed bearing.

EAM30150

CHECKING THE CRANKCASE1. Wash:

• CrankcaseTIP• Wash the crankcase in a mild solvent.• Remove any remaining gasket from the crank-

case mating surface.

2. Check:• Crankcase

Crack/damage Replace.• Oil delivery passages

Obstruction Blow out with compressed air.

EAM30152

ASSEMBLING THE CRANKCASE1. Install:

• Bearing “1” (to crankcase (left/right))

TIP• Apply the engine oil on the bearing.• Install the bearing by pressing its outer race

parallel.

2. Install:• Oil seal (left) “1” • Oil seal (right) “2”

TIP• Apply the lithium soap base grease on the oil

seal lip.• Install the oil seal with its manufacture’s marks


Crankcase separating tool90890-01135

Crankcase separatorYU-01135-B

New

NewNew

CRANKCASE

5-38

3. Apply:• Sealant

(on the crankcase (right) “1”)

TIPClean the contacting surface of crankcase(left/right) before applying the sealant.

4. Install:• Dowel pin “1”• O-ring “2”

5. Install:• Crankcase (right) “1”

Use the crankshaft installing tools “2”, “3”, “4”.

TIP• Apply molybdenum disulfide grease to the sur-

face “a” where the crankshaft and bearingcome in contact.

• If you use the tools starting from “90890-”, in-stead of the spacer “5” use two plain washers(Yamaha genuine: 90201-243K3) “6” or theones of a size as shown placed on top of eachother.

• If you use the washers in the installation, installthe washers so that they do not deviate fromthe crankshaft center.

• When installing the crankcase, the connectingrod should be positioned at TDC (top deadcenter).

• Make sure that the dowel pin is in place.

6. Install:• Holder “1”• Holder bolt “2”

Yamaha bond No. 121590890-85505(Three bond No.1215®)

1 2

1–2 mm(0.04–0.08 in)

1–2 mm(0.04–0.08 in)

New

Crankshaft installer pot90890-01274

Installing potYU-90058

Crankshaft installer bolt90890-01275

BoltYU-90060

Adapter (M8)90890-01499

Adapter (M8)YM-01499

Holder bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)LOCTITE®

M

a

3

12

46

5 4–5 mm(0.16–0.20 in)

25–38 mm(0.98–1.50 in)

45–50 mm(1.77–1.97 in)

TR..

CRANKCASE

5-39

7. Install:• Clamp “1”• Crankcase bolt “2”

TIPTighten the crankcase bolts in stage, using acrisscross pattern.

Crankcase bolt14 N·m (1.4 kgf·m, 10 lb·ft)

LT

1

2

TR..

CRANKSHAFT

5-40

EAM20193

CRANKSHAFTRemoving the crankshaft assembly


Engine Refer to “ENGINE REMOVAL” on page 5-1.Crankcase Separate.

1 Crankshaft 1


13

3

2

2

CRANKSHAFT

5-41

EAM30491

REMOVING THE CRANKSHAFT1. Remove:

• Crankshaft “1”(with the crankcase separating tool “2”)

TIPMake appropriate bolts “3” as shown availableby yourself and attach the tool with them.

NOTICEECA22290

Do not use a hammer to drive out the crank-shaft.

EAM30492

CHECKING THE CRANKSHAFT1. Measure:

• Crankshaft runoutOut of specification Replace the crank-shaft, bearing or both.

TIPTurn the crankshaft slowly.

2. Measure:• Crank assembly width “a”

Out of specification Replace the crank-

shaft.

EAM30493

INSTALLING THE CRANKSHAFT1. Install:

• Crankshaft assembly “1”TIPInstall the crankshaft assembly with the crank-shaft installer pot “2”, crankshaft installer bolt “3”,and adapter (M12) “4”.

NOTICEECA26470

In order to prevent the crankshaft seizure,apply molybdenum disulfide grease.

NOTICEECA23810

Do not use a hammer to drive in the crank-shaft.

TIP• Hold the connecting rod at top dead center

(TDC) with one hand while turning the nut ofthe crankshaft installer bolt with the other. Turnthe crankshaft installer bolt until the crankshaftassembly bottoms against the bearing.

• Before installing the crankshaft, clean the con-tacting surface of crankcase.

• Apply the lithium soap base grease on the oil

Crankcase separating tool90890-01135

Crankcase separatorYU-01135-B

Runout limit0.050 mm (0.0020 in)

Crank assembly width55.90–55.95 mm (2.201–2.203 in)

Crankshaft installer pot90890-01274

Installing potYU-90058

Crankshaft installer bolt90890-01275

BoltYU-90060

Adapter (M12)90890-01278

Adapter #3YU-90063

CRANKSHAFT

5-42

seal lip.

4

1

2 3

M

TRANSMISSION

5-43

EAM20118

TRANSMISSIONRemoving the transmission, shift drum assembly, and shift forks


Engine Refer to “ENGINE REMOVAL” on page 5-1.Crankcase Refer to “CRANKCASE” on page 5-36.

1 Guide bar (long) 1

2 Guide bar (short) 13 Shift cam 1

4 Shift fork 3 (R) 1

5 Shift fork 1 (L) 16 Shift fork 2 (C) 1

7 Main axle 1

8 Drive axle 19 Collar 1

1

2

3

4

5

6

7

8

9

10 N・m (1.0 kgf・m, 7.4 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

TRANSMISSION

5-44

EAM30153

REMOVING THE TRANSMISSION1. Remove:

• Main axle “1”• Drive axle “2”

TIP• Tap lightly on the transmission drive axle with

a soft hammer to remove.• Remove assembly carefully. Note the position

of each part. Pay particular attention to the lo-cation and direction of shift forks.

EAM30154

CHECKING THE SHIFT FORKS1. Check:

• Shift fork “1”Wear/damage/scratches Replace.

2. Check:• Shift fork movement

Unsmooth operation Replace shift fork.TIPFor a malfunctioning shift fork, replace not onlythe shift fork itself but the two gears each adja-cent to the shift fork.

EAM30155

CHECKING THE SHIFT DRUM ASSEMBLY1. Check:

• Shift drum grooveDamage/scratches/wear Replace the shiftdrum assembly.

• Shift drum segmentDamage/wear Replace the shift drum as-sembly.

EAM30156

CHECKING THE TRANSMISSION1. Measure:

• Main axle runout(with a centering device and dial gauge “1”)Out of specification Replace the main axle.

2. Measure:• Drive axle runout

(with a centering device and dial gauge “1”)Out of specification Replace the drive axle.

Main axle runout limit0.01 mm (0.0004 in)

Drive axle runout limit0.01 mm (0.0004 in)

TRANSMISSION

5-45

3. Check:• Transmission gears

Blue discoloration/pitting/wear Replacethe defective gear(s).

• Transmission gear dogsCracks/damage/rounded edges Replacethe defective gear(s).

4. Check:• Transmission gear movement

Rough movement Replace the defectivegear(s).

EAM30157

INSTALLING THE TRANSMISSION1. Install:

• 6th pinion gear (21T) “1”• 3rd/4th pinion gear (17T/17T) “2”• 5th pinion gear (20T) “3”• 2nd pinion gear (15T) “4”

(to main axle “5”)TIPApply the molybdenum disulfide oil on the innerand end surface of the idler gear and on the in-ner surface of the sliding gear, then install.

2. Install:• 2nd wheel gear (29T) “1”• 5th wheel gear (24T) “2”• 3rd wheel gear (27T) “3”• 4th wheel gear (23T) “4”• 6th wheel gear (23T) “5”• 1st wheel gear (31T) “6”

(to drive axle “7”)

TIP• Apply the molybdenum disulfide oil on the in-

ner and end surface of the idler gear and on theinner surface of the sliding gear, then install.

• Apply the molybdenum disulfide grease on theinner surface of the 4th wheel gear, then install.

3. Install:• Washer “1”• Circlip “2”

TIP• Be sure the circlip sharp-edged corner “a” is

positioned opposite side to the washer andgear “b”.

• Be sure the circlip end “c” is positioned at axlespline groove “d”.


TIP• Apply the lithium soap base grease on the oil

seal lip.

New

TRANSMISSION

5-46

• When installing the collar into the crankcase,pay careful attention to the crankcase oil seallip.

5. Install:• Shift fork 1 (L) “1”• Shift fork 2 (C) “2”• Shift fork 3 (R) “3”

TIP• Apply the molybdenum disulfide oil on the shift

fork grooves.• Mesh the shift fork 1 (L) with the 5th wheel gear

“4” and 3 (R) with the 6th wheel gear “6” on thedrive axle.

• Mesh the shift fork 2 (C) with the 3rd/4th piniongear “5” on the main axle.

6. Install:• Shift cam “1”

TIP• Apply the transmission oil on the shift cam.• Install the shift cam while holding up the 5th

wheel gear “2” and keeping the shift fork 1 “3”moved in the direction of the arrow.

7. Install:• Guide bar (short) “1”• Guide bar (long) “2”

TIP• Apply the transmission oil on the guide bars.• Be sure the long bar is inserted into the shift

forks 1 and 3 and the short one into 2.

8. Check:• Shifter operation• Transmission operation

Unsmooth operation Repair.

1

1

2

3

4

5

6

7

8

9

10

COOLING SYSTEM

COOLING SYSTEM DIAGRAMS .....................................................................6-1

RADIATOR ........................................................................................................6-2CHECKING THE RADIATOR .....................................................................6-3INSTALLING THE RADIATOR ...................................................................6-3

WATER PUMP ..................................................................................................6-5DISASSEMBLING THE WATER PUMP.....................................................6-6CHECKING THE WATER PUMP ...............................................................6-6ASSEMBLING THE WATER PUMP...........................................................6-6

COOLING SYSTEM DIAGRAMS

6-1

EAM20186

COOLING SYSTEM DIAGRAMS

1. Radiator hose 12. Radiator (right)3. Radiator hose 44. Water pump5. Radiator (left)

RADIATOR

6-2

EAM20138

RADIATORRemoving the radiator


CoolantDrain.Refer to “CHANGING THE COOLANT” on page 3-11.



1 Radiator guard 22 Radiator hose clamp (radiator hose 1, 3) 2 Only loosening.

3 Radiator hose 2 1

4 Radiator (left) 15 Radiator hose 4 1

6 Radiator (right) 1

7 Radiator hose 1 18 Radiator hose 3 1

9 Radiator breather hose 1

1

2

3

4

5

6

7

8

9

1.5 N・m (0.15 kgf・m, 1.1 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

1.5 N・m (0.15 kgf・m, 1.1 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

1

2

RADIATOR

6-3

EAM30341

CHECKING THE RADIATOR

WARNINGEWA13030


1. Check:• Radiator fin

Obstructions Clean.Apply compressed air to the rear of the radia-tor.Damage Repair or replace.

TIPCorrect any flattened fins with a thin, flat-headscrewdriver.

2. Check:• Radiator hose• Radiator pipe

Crack/damage Replace.3. Check:

• Radiator cap valve opening pressurea. Install the radiator cap tester adapter “2”

and the radiator cap tester “1” to the radi-ator cap “3”, and activate the tester tocheck whether it can stay for 5 to 10 sec-onds within standard pressure values.

TIPBefore attaching the cap to the tester, apply wa-ter to its sealing surface.

No stay Replace.

EAM30506

INSTALLING THE RADIATOR1. Fill:

• Cooling system(with the specified amount of the recom-mended coolant)Refer to “CHANGING THE COOLANT” onpage 3-11.

2. Check:• Cooling system

Leaks Repair or replace any faulty part.3. Install:

• Radiator cap tester “1”• Radiator cap tester adapter “2”

G089028

Radiator cap valve opening pres-sure

93.3–122.7 kPa (0.93–1.23 kgf/cm², 13.5–17.8 psi)

Radiator cap tester90890-01325

Mityvac cooling system tester kitYU-24460-A

Radiator cap tester adapter90890-01352

Pressure tester adapterYU-33984

Radiator cap tester90890-01325

Mityvac cooling system tester kitYU-24460-A

Radiator cap tester adapter90890-01352

Pressure tester adapterYU-33984

G089029

RADIATOR

6-4

4. Activate the tester to apply the test pressure.

NOTICEECA24270

• Do not apply such a high pressure as ex-ceeds the test pressure.

• Make sure that a checkup after the cylinderhead gasket is replaced is made after 3 min-utes of warm-up.

• Make sure that coolant is filled up to the up-per level beforehand.

5. Check:• Pressure value

No stay for 5 to 10 seconds at the test pres-sure value Correct.

• Radiator• Radiator hose connections

Coolant leaks Correct or replace.• Radiator hose

Bulges Replace.

WARNINGEWA19090

When the radiator cap tester is removed,coolant will spout; therefore, cover it with acloth beforehand.

Test pressure value122.7 kPa (1.23 kgf/cm², 17.8 psi)

1

2

G089031

WATER PUMP

6-5

EAM20139

WATER PUMPRemoving the water pump


Crankcase cover (right) Refer to “KICKSTARTER” on page 5-18.1 Water pump housing cover 1

2 Impeller shaft gear 1

3 Dowel pin 14 Washer 1

5 Impeller shaft assembly 1

6 Bearing 17 Oil seal 2

10 N・m (1.0 kgf・m, 7.4 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

1

2

3

4

5

6

7

7

WATER PUMP

6-6

EAM30494

DISASSEMBLING THE WATER PUMPTIP• Remove the oil seal when the coolant level

changes frequently more than usual, coolanthas discolored, or engine oil has becomemilky.

• Do not use the removed oil seal.

1. Remove:• Oil seal “1”, “2”

EAM30259

CHECKING THE WATER PUMP1. Check:

• Water pump housing cover• Impeller shaft• Impeller

Cracks/damage/wear Replace.2. Check:

• Bearing “1”Rotate the inner race with your finger.Rough spot/seizure Replace.

EAM30262

ASSEMBLING THE WATER PUMP1. Install:

• Oil seal “1”, “2” TIP• Apply the lithium-soap-based grease on the oil

seal lip.• Install the oil seal with its manufacture’s marks

or numbers facing the crankcase cover (right)“3”.

2. Install:• Bearing “1”

TIPInstall the bearing by pressing its outer race par-allel.

3. Install:• Impeller shaft “1”

TIP• Take care so that the oil seal lip is not dam-

aged or the spring does not slip off its position.• When installing the impeller shaft, apply the

lithium soap base grease on the oil seal lip andimpeller shaft. And install the shaft while turn-ing it.

4. Install:• Washer “1”, “5”• Dowel pin “2”

New

Impeller14 N·m (1.4 kgf·m, 10 lb·ft)

3 1

2

New

TR..

1

WATER PUMP

6-7

• Impeller shaft gear “3”• Collar “4”• Circlip “6”

TIPInstall the impeller shaft gear with the dowel pinfitted in the groove “a” in the same gear.

5. Install:• Dowel pin “1”• Gasket “2”

6. Install:• Water pump housing “1”• Water pump housing cover bolt “2”

• Copper washer “3” • Coolant drain bolt “4”

Water pump housing cover bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)

Coolant drain bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)

New

New

TR..

New

TR..

1

2

3

4

5

6

7

8

9

10

FUEL SYSTEM

FUEL TANK ......................................................................................................7-1

AIR FILTER .......................................................................................................7-2

CARBURETOR .................................................................................................7-3HANDLING NOTE ......................................................................................7-5CHECKING THE CARBURETOR ..............................................................7-5CHECKING THE REED VALVE .................................................................7-6INSTALLING THE REED VALVE ...............................................................7-7ASSEMBLING THE CARBURETOR ..........................................................7-7INSTALLING THE CARBURETOR ............................................................7-9MEASURING AND ADJUSTING THE FUEL LEVEL................................7-10

FUEL TANK

7-1

EAM20140

FUEL TANKRemoving the fuel tank



Side cover (left/right)

Air scoop (left/right)

1 Fitting band 12 Fuel cock assembly 1

3 O-ring 1

4 Fuel tank 15 Fuel tank breather hose 2

6 Valve joint 1

10 N・m (1.0 kgf・m, 7.4 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

4.0 N・m (0.40 kgf・m, 3.0 lb・ft)

7 N・m (0.7 kgf・m, 5.2 lb・ft)

2

1

4

5

6

(4)

(2)

3

AIR FILTER

7-2

EAM20201

AIR FILTERRemoving the air filter element



1 Fitting bolt 1

2 Air filter element 1

3 Air filter guide 14 Guide holder 1

5 Band 1

6 Spacer 17 Air filter joint 1

8 Air filter case 1

2

3

4

5

6

7

(3)

(3)

1

8

8 N・m (0.8 kgf・m, 5.9 lb・ft)

2.0 N・m (0.20 kgf・m, 1.5 lb・ft)

8 N・m (0.8 kgf・m, 5.9 lb・ft)

3.5 N・m (0.35 kgf・m, 2.6 lb・ft)

CARBURETOR

7-3

EAM20194

CARBURETORRemoving the carburetor and reed valve


Fuel tank Refer to “FUEL TANK” on page 7-1.1 Carburetor joint clamp 2

2 Carburetor 1

3 Carburetor joint 14 Reed valve assembly 1

5 Reed valve stopper 2

6 Reed valve 2

1

23

45

6

2.3 N・m (0.23 kgf・m, 1.7 lb・ft)

10 N・m (1.0 kgf・m, 7.4 lb・ft)

1.0 N・m (0.10 kgf・m, 0.73 lb・ft)

2.3 N・m (0.23 kgf・m, 1.7 lb・ft)

1

CARBURETOR

7-4

Disassembling the carburetor


1 Mixing chamber top 1

2 Throttle valve 1

3 Needle holder 14 Jet needle 1

5 Float chamber 1

6 Needle jet cover 17 Float pin 1

8 Float 1

9 Valve seat 110 Main jet 1

11 Main jet holder 1

12 Pilot jet 113 Starter plunger 1

14 Throttle stop screw 1

15 Pilot air screw 1

1

2

3

4

5

6

78

9

10

11

12

1314

15

4.0 N・m (0.40 kgf・m, 3.0 lb・ft)

CARBURETOR

7-5

EAM30580

HANDLING NOTE

NOTICEECA27150

Do not disassemble the venturi block “1”and main nozzle “2” because it will cause adrop in carburetor performance.

EAM30573

CHECKING THE CARBURETOR1. Check:

• Carburetor body• Float chamber• Jet housing

Cracks/damage Replace.2. Check:

• Air passageObstruction Clean.

NOTICEECA27160

When cleaning the main air passage, do notblow air at the filter side because it will clogthe passage with mud or sand.

TIP• Use a petroleum based solvent for cleaning.

Blow out all passages and jets with com-pressed air.

• Never use a wire.• When cleaning the main air passage, blow air

through it while covering the nozzle with aclean rag.

3. Check:• Fuel passages

Obstruction Clean.a. Wash the carburetor in a petroleum-based

solvent. Do not use any caustic carburetorcleaning solution.

b. Blow out all of the passages and jets withcompressed air.

4. Check:• Float chamber body

Dirt Clean.5. Check:

• Float chamber rubber gasketCracks/damage/wear Replace.

6. Check:• Float

Damage Replace.

7. Check:• Needle valve “1”• Needle valve seat “2”

Damage/wear “a” Replace.Obstruction “b” Clean.

a. Main air passage

a

1

2

b

CARBURETOR

7-6

8. Check:• Jet needle “1”

Bends/damage/wear Replace.Obstruction Clean.

9. Check:• Main jet “1”• Main jet holder “2”• Pilot jet “3”

TIP• Use a petroleum based solvent for cleaning.

Blow out all passages and jets with com-pressed air.

• Never use a wire.

10.Check:• Filter “1”

Damage Replace.TIPInspect the filter as it is assembled to the carbu-retor. Do not remove the filter except when re-placing it.

11.Check:• Free movement

Stick Repair or replace.TIPInsert the throttle valve “1” into the carburetorbody and check for free movement.

12.Check:• Hose joints

Cracks/damage Replace.13.Check:

• Carburetor breather hoses• Fuel hoses

Cracks/damage/wear Replace.Obstruction Clean.Blow out the hoses with compressed air.

EAM30574

CHECKING THE REED VALVE1. Measure:

• Reed valve bending “a”Out of limit Replace.

Standard clip positionNo. 3 groove

Valve bending limit0.2 mm (0.01 in)

CARBURETOR

7-7

• Valve stopper height “b”Out of specification Replace.

EAM30577

INSTALLING THE REED VALVE1. Install:

• Reed valve “1”• Reed valve stopper “2”• Reed valve screw “3”

TIP• Install the reed valve with the reed valve bend-

ing as shown.• Note the cut “a” in the lower corner of the reed

valve and stopper.• Tighten each screw gradually to avoid warping.

2. Install:• Reed valve assembly “1”• Reed valve spacer “2”

3. Install:• Carburetor joint “1”• Carburetor joint bolt “2”

EAM30576

ASSEMBLING THE CARBURETOR1. Install:

• Throttle stop screw “1”• Locknut “2”• Pilot air screw “3”

a. Turn in the pilot air screw until it is lightlyseated.

b. Turn out the pilot air screw by the numberof turns recorded before removing.

Valve stopper height8.2–8.6 mm (0.32–0.34 in)

Reed valve screw1.0 N·m (0.10 kgf·m, 0.73 lb·ft)

bb

TR..

Carburetor joint bolt10 N·m (1.0 kgf·m, 7.4 lb·ft)

Air screw turns out2-1/4

TR..

CARBURETOR

7-8

2. Install:• Starter plunger “1”

3. Install:• Main jet holder “1”• Main jet “2”• Pilot jet “3”• Valve seat “4”• Valve seat holding screw “5”

4. Install:• Needle valve “1”• Float “2”• Float pin “3”• Float pin screw “4”• Needle jet cover “5”

TIP• After installing the needle valve to the float, in-

stall them to the carburetor.• Check the float for smooth movement.

5. Install:• Float chamber “1”• Plate “2”• Screw (float chamber) “3”

6. Install:• Jet needle “1”• Needle holder “2”

(to throttle valve “3”)

7. Install:• Throttle cable “1”• Locknut “2”

• Mixing chamber top “3”• Spring (throttle valve) “4”• Ring “5”• Throttle valve “6”

TIP• While compressing the spring, connect the

Locknut (throttle cable carburetor side)

4.0 N·m (0.40 kgf·m, 3.0 lb·ft)

TR..

CARBURETOR

7-9

throttle cable.• Align the projection “a” on the ring with the

groove “b” in the needle holder “7”.

8. Install:• Mixing chamber top “1”• Screw (mixing chamber top) “2”

(to carburetor “3”)TIPAfter installing, check the throttle grip for smoothmovement.

9. Install:• Air vent hose “1”• Overflow hose [L = 280 mm (11.0 in)] “2”• Clamp “3”

Refer to “CABLE ROUTING DIAGRAM” onpage 2-15.

TIPPass the air vent hose at the rear (on the aircleaner side) of the throttle cable “4”.

EAM30578

INSTALLING THE CARBURETOR1. Install:

• Carburetor “1”TIPInstall the projection between the carburetorjoint slots.

2. Tighten:• Air filter case joint clamp “1”• Carburetor joint clamp “2”

3. Clamp:• Air vent hose “1”• Overflow hose “2”

Refer to “CABLE ROUTING DIAGRAM” onpage 2-15.

Air filter case joint clamp2.3 N·m (0.23 kgf·m, 1.7 lb·ft)

Carburetor joint clamp2.3 N·m (0.23 kgf·m, 1.7 lb·ft)

TR..

CARBURETOR

7-10

4. Adjust:• Idle speed

Refer to “CHECKING THE ENGINE IDLINGSPEED” on page 3-5.

EAM30579

MEASURING AND ADJUSTING THE FUEL LEVEL1. Measure:

• Fuel level “a”Out of specification Adjust.

a. Remove the drain plug.b. Connect the fuel level gauge adapter “2”

and fuel level gauge “1” to the float cham-ber.

c. Hold the fuel level gauge vertically next tothe float chamber mating surface.

d. Measure the fuel level with the fuel levelgauge.

TIPKeep the carburetor and fuel level gauge verti-cally when measuring the fuel level.

e. If the fuel level is not within specification,inspect the valve seat and needle valve.

f. If either is worn, replace them both.g. If both are fine, adjust the fuel level by

bending the float tab “b” on the float.h. Recheck the fuel level.

Fuel level (using fuel level gauge)9.5–10.5 mm (0.37–0.41 in)Above the float chamber mating surface

Fuel level gauge adapter90890-01470

Fuel level gauge adapterYM-01470

Fuel level gauge90890-01312

Fuel level gaugeYM-01312-A

CARBURETOR

7-11

1

2

3

4

5

6

7

8

9

10

ELECTRICAL SYSTEM

WIRING DIAGRAM ...........................................................................................8-1COLOR CODE............................................................................................8-1

IGNITION SYSTEM...........................................................................................8-2TROUBLESHOOTING................................................................................8-2

ELECTRICAL COMPONENTS.........................................................................8-3CHECKING THE SWITCHES.....................................................................8-4CHECKING THE IGNITION SPARK GAP..................................................8-6CHECKING THE SPARK PLUG CAP ........................................................8-6CHECKING THE IGNITION COIL ..............................................................8-6CHECKING THE PICKUP COIL.................................................................8-7CHECKING THE SOURCE COIL...............................................................8-7

WIRING DIAGRAM

8-1

EAM20195

WIRING DIAGRAM

EAM30608

COLOR CODE

1. Engine stop switch2. CDI unit3. Ignition coil4. CDI magneto5. Spark plug

B BlackO OrangeY YellowB/R Black/RedB/W Black/WhiteG/L Green/BlueG/W Green/WhiteW/L White/BlueW/R White/Red

IGNITION SYSTEM

8-2

EAM20142

IGNITION SYSTEMEAM30278

TROUBLESHOOTINGThe ignition system fails to operate (no spark or intermittent spark).TIPBefore troubleshooting, remove the following part(s):1. Seat2. Fuel tank

1. Check the spark plug.Refer to “CHECKING THE SPARK PLUG” on page 3-5. NG

Re-gap or replace the spark plug.

OK

2. Check the ignition spark gap.Refer to “CHECKING THE IGNI-TION SPARK GAP” on page 8-6. OK

Ignition system is OK.

NG

3. Check the spark plug cap.Refer to “CHECKING THE SPARK PLUG CAP” on page 8-6. NG

Replace the spark plug cap.

OK

4. Check the ignition coil.Refer to “CHECKING THE IGNI-TION COIL” on page 8-6. NG

Replace the ignition coil.

OK

5. Check the engine stop switch.Refer to “CHECKING THE SWITCHES” on page 8-4. NG

Replace the engine stop switch.

OK

6. Check the pickup coil.Refer to “CHECKING THE PICKUP COIL” on page 8-7. NG

Replace the pickup coil.

OK

7. Check the source coil.Refer to “CHECKING THE SOURCE COIL” on page 8-7. NG

Replace the CDI magneto.

OK

8. Check the entire ignition system wir-ing.Refer to “WIRING DIAGRAM” on page 8-1.

NGProperly connect or replace the wiring har-ness.

OK

Replace the CDI unit.

ELECTRICAL COMPONENTS

8-3

EAM20147


1

2

3

1. Engine stop switch2. CDI unit3. Ignition coil


8-4

EAM30289

CHECKING THE SWITCHES

1

1. Engine stop switch


8-5

Check each switch for continuity with the digital circuit tester. If the continuity reading is incorrect, checkthe wiring connections and if necessary, replace the switch.

NOTICEECA14371

Never insert the tester probes into the coupler terminal slots. Always insert the probes from theopposite end “a” of the coupler, taking care not to loosen or damage the leads.

TIPWhen checking for continuity, switch back and forth between the switch positions a few times.

Terminal connections of the switch are shown in the terminal connection diagram below.The switch positions “a” are shown in the far left column and the switch lead colors are shown in thetop row in the switch illustration.TIP“ ” indicates continuity between switch terminals (i.e., a closed circuit at each switch position).

The example illustration below shows that:There is continuity between red and brown when the switch is “ON”.



YU-A1927

a


8-6

EAM30294

CHECKING THE IGNITION SPARK GAP1. Check:

• Ignition spark gapOut of specification Perform the ignitionsystem troubleshooting, starting with step (3).Refer to “TROUBLESHOOTING” on page8-2.

TIPIf the ignition spark gap is within specification,the ignition system circuit is operating normally.

a. Disconnect the spark plug cap from thespark plug.

b. Connect the ignition checker “1” asshown.

c. Kick the kickstarter crank.d. Measure the ignition spark gap “a”.e. Crank the engine and gradually increase

the spark gap until a misfire occurs.

EAM30295

CHECKING THE SPARK PLUG CAP1. Remove:

• Spark plug cap(from the high tension cord)

2. Check:• Spark plug cap resistance


a. Connect the digital circuit tester () to thespark plug cap.

b. Measure the spark plug cap resistance.

EAM30296

CHECKING THE IGNITION COIL1. Check:

• Primary coil resistanceOut of specification Replace.

a. Disconnect the ignition coil connectorsfrom the ignition coil terminals.

b. Connect the digital circuit tester () to theignition coil as shown.

Minimum ignition spark gap6.0 mm (0.24 in)

Ignition checker90890-06754

Oppama pet–4000 spark checkerYM-34487

2. Spark plug cap

Resistance5.00 k

G089048



YU-A1927

• Positive tester probe High tension cord terminal “1”

• Negative tester probe High tension cord terminal “2”

Primary coil resistance0.24–0.36



YU-A1927

• Positive tester probe Yellow “1”

• Negative tester probe Black “2”

2

1


8-7

c. Measure the primary coil resistance.2. Check:

• Secondary coil resistanceOut of specification Replace.

a. Connect the digital circuit tester () to theignition coil as shown.

b. Measure the secondary coil resistance.

EAM30583

CHECKING THE PICKUP COIL1. Disconnect:

• Pickup coil coupler(from the wire harness)

2. Check:• Pickup coil resistance


a. Connect the digital circuit tester () to thepickup coil coupler as shown.

b. Measure the pickup coil resistance.

EAM30584

CHECKING THE SOURCE COIL1. Disconnect:

• CDI magneto coupler(from the wire harness)

2. Check:• Charging coil 1 resistance

(B/R–G/W)Out of specification Replace the CDI mag-neto.

a. Connect the digital circuit tester () to theCDI magneto coupler as shown.

Secondary coil resistance5.68–8.52 k



YU-A1927

• Positive tester probe High tension cord “1”

• Negative tester probe Yellow “2”

Pickup coil resistance248.0–372.0



YU-A1927

• Positive tester probe White/Red “1”

• Negative tester probe White/Blue “2”

Charging coil 1 resistance720.0–1080.0



YU-A1927

• Positive tester probe Black/Red “1”

• Negative tester probe Green/White “2”


8-8

b. Measure the source coil resistance (B/R–G/W).

3. Check:• Charging coil 2 resistance

(G/L–B)Out of specification Replace the CDI mag-neto.

a. Connect the digital circuit tester () to theCDI magneto coupler as shown.

b. Measure the source coil resistance (G/L–B).

Charging coil 2 resistance44.0–66.0



YU-A1927

• Positive tester probe Green/Blue “1”

• Negative tester probe Black “2”


8-9

1

2

3

4

5

6

7

8

9

10

TROUBLESHOOTING

TROUBLESHOOTING ......................................................................................9-1GENERAL INFORMATION ........................................................................9-1TROUBLESHOOTING OF ENGINE...........................................................9-1TROUBLESHOOTING OF CLUTCH ..........................................................9-6TROUBLESHOOTING OF TRANSMISSION .............................................9-7TROUBLESHOOTING OF COOLING SYSTEM ........................................9-8TROUBLESHOOTING OF BRAKE ............................................................9-9TROUBLESHOOTING OF SUSPENSION .................................................9-9TROUBLESHOOTING OF STEERING/HANDLING.................................9-11

TROUBLESHOOTING

9-1

EAM20148

TROUBLESHOOTINGEAM30309

GENERAL INFORMATIONTIPTroubleshooting information provided here does not cover all the trouble symptoms, possible causes,and remedial actions. Some items may not apply depending on the model. Use this information as aguide and quick reference matrix when performing basic troubleshooting. Refer to the each chapter fordetailed information on checking, adjustment, and replacement.

EAM30612

TROUBLESHOOTING OF ENGINEEngine will not start or is difficult to start, but it cranks.

Symptom Possible cause Actions

Spark plug does not produce a spark

Refer to “TROUBLESHOOTING” under “IGNITION SYSTEM” on page 8-2.

Fuel not supplied

Empty fuel tank Fill the fuel tank with fuel.

Clogged fuel tank cap breather hole Clean the fuel tank cap.

Clogged or damaged fuel hose Clean, repair, or replace the fuel hose.

Fuel leakage Check the fuel passage. Repair or replace as necessary.

Clogged fuel cock strainer Clean or replace the fuel cock strainer.

Clogged fuel cock Clean or replace the fuel cock.

Cracked, damaged or worn fuel cock Replace the fuel cock.

Clogged carburetor fuel passage Clean the carburetor.

Clogged needle valve or needle valve seat

Clean the needle valve or needle valve seat.

Damaged float Replace the float.

Clogged pilot jet Clean the pilot jet.

Clogged starter jet Clean the starter jet.

Bent or damaged starter plunger Replace the starter plunger.

Incorrectly adjusted starter cable Adjust the starter cable.

— Water or foreign material in fuel, degraded fuel Change fuel.

TROUBLESHOOTING

9-2

Incorrect idling speed or mid-to-high speed

Compression pressure is low

— Measure the compression pres-sure.

Loose spark plug Tighten the spark plugs to the specified torque.

Loose cylinder head or cylinderTighten bolts or nuts on cylinder head and cylinder to the specified torque.

Damaged cylinder head gasket Replace the cylinder head gasket.

Worn, damaged, or stuck piston ring

Replace the piston and piston rings as a set.

Seized or damaged piston Replace the piston and piston rings as a set.

Worn or damaged cylinder bore Replace the cylinder, piston, and piston rings as a set.



Incorrect spark plug gap Adjust the spark plug gap.

Worn or damaged spark plug Replace the spark plug.

Defective spark plug cap Replace the spark plug cap.

Defective ignition coil Replace the ignition coil.

CDI unit failure Replace the CDI unit.

Fuel not supplied






—

Water or foreign material in fuel, degraded fuel Change fuel.

Clogged carburetor air passage Clean the carburetor.

Incorrectly adjusted throttle cable Adjust the throttle grip free play.

Incorrectly adjusted idling speed (throttle stop screw) Adjust the throttle stop screw.

Incorrectly adjusted pilot screw Adjust the pilot screw.

Incorrectly adjusted pilot air screw Adjust the pilot air screw.


Loose pilot jet Tighten the pilot jet to the specified torque.

Damaged or worn needle valve seat Replace the needle valve seat.

Loose needle valve seat Tighten the needle valve seat to the specified torque.


TROUBLESHOOTING

9-3

Incorrect mid-high speed

—

Damaged or worn needle valve Replace the needle valve.

Incorrect fuel level Adjust the fuel level to the proper level.

Bent, worn, or damaged starter plunger Replace the starter plunger.


Clogged or damaged carburetor breather hose

Clean, repair, or replace the car-buretor breather hose.

Incorrect throttle position sensor angle

Adjust the throttle position sensor angle.

Failed air induction system Check the air induction system. Repair or replace faulty parts.

Clogged vacuum hose Clean the vacuum hose.

Cracks and damage in vacuum hose Replace the vacuum hose.

Damaged carburetor joint Replace the carburetor joint.

Loose carburetor joint Tighten the carburetor joint bolts to the specified torque.

Clogged air filter element Clean or replace the air filter ele-ment.



Incorrect spark plug gap Adjust the spark plug gap.

Worn or damaged spark plug Replace the spark plug.

Defective spark plug cap Replace the spark plug cap.

Defective ignition coil Replace the ignition coil.

CDI unit failure Replace the CDI unit.

Fuel not supplied







TROUBLESHOOTING

9-4

—

Water or foreign material in fuel, degraded fuel Change fuel.

Clogged carburetor air passage Clean the carburetor.

Incorrectly adjusted throttle cable Adjust the throttle grip free play.

Improperly synchronized carbure-tors

Adjust synchronization of carbure-tors.

Incorrectly adjusted pilot screw Adjust the pilot screw.

Incorrectly adjusted pilot air screw Adjust the pilot air screw.


Loose pilot jet Tighten the pilot jet to the specified torque.

Clogged main nozzle Clean the main nozzle.

Loose main nozzle Tighten the main nozzle to the specified torque.

Clogged main jet Clean the main jet.

Loose main jet Tighten the main jet to the speci-fied torque.

Bent, damaged, or worn jet needle Replace the jet needle.

Cracks or damage in the piston valve diaphragm

Replace the piston valve dia-phragm.

Problem with piston valve move-ment (movement is not smooth) Replace the piston valve.

Damaged or worn needle valve seat Replace the needle valve seat.

Loose needle valve seat Tighten the needle valve seat to the specified torque.

Damaged or worn needle valve Replace the needle valve.

Incorrect fuel level Adjust the fuel level to the proper level.

Bent, worn, or damaged starter plunger Replace the starter plunger.


Clogged or damaged carburetor breather hose

Clean, repair, or replace the car-buretor breather hose.

Incorrect throttle position sensor angle

Adjust the throttle position sensor angle.


TROUBLESHOOTING

9-5

Excessive noise from engine

—

Failed air induction system Check the air induction system. Repair or replace faulty parts.

Clogged vacuum hose Clean the vacuum hose.

Cracks and damage in vacuum hose Replace the vacuum hose.

Damaged carburetor joint Replace the carburetor joint.

Loose carburetor joint Tighten the carburetor joint bolts to the specified torque.



Noise heard from around piston

Worn or damaged piston ring Replace the piston and piston rings as a set.

Worn or damaged piston Replace the piston and piston rings as a set.

Worn piston (piston pin hole) Replace the piston and piston pin as a set.

Worn or damaged piston pin Replace the piston pin.

Worn or damaged cylinder bore Replace the cylinder, piston, and piston rings as a set.

Carbon buildup in piston head and combustion chamber

Clean the piston head and com-bustion chamber.

Noise heard from around crank-shaft

Worn or damaged crankshaft jour-nal or crank pin Replace the crankshaft.

Worn or damaged big end bearing Replace the big end bearing.

Worn or damaged crankshaft jour-nal bearing

Replace the crankshaft journal bearing.

Worn or damaged balancer shaft journal bearing

Replace the balancer shaft journal bearing.


TROUBLESHOOTING

9-6

EAM30510

TROUBLESHOOTING OF CLUTCHManual clutch


Clutch slippage

Improperly assembled clutch Reassemble the clutch.

Improperly adjusted clutch cable Adjust the clutch lever free play.

Loose clutch spring Tighten the clutch spring bolts to the specified torque.

Fatigued clutch spring Replace the clutch springs as a set.

Warped pressure plate Replace the pressure plate.

Worn friction plate Replace the friction plates as a set.

Warped or worn clutch plate Replace the clutch plates as a set.

Incorrect oil level Adjust the engine oil level to the specified level.

Incorrect oil viscosity (low) Change to recommended engine oil.

Deteriorated oil Change to recommended engine oil.

Clutch drags

Faulty clutch spring Replace the clutch springs as a set.

Warped pressure plate Replace the pressure plate.

Swollen friction plate Replace the friction plates as a set.

Warped clutch plate Replace the clutch plates as a set.

Bent pull rod (outer pull type) Replace the pull rod.

Worn pull rod tooth (outer pull type)

Replace the pull rod and pull lever shaft as a set.

Bent push rod (inner push type) Replace the push rod.

Damaged or worn clutch boss Replace the clutch boss.

Seized clutch housing bushing Replace the clutch housing.

Improperly installed pull lever Align the match mark on the pull lever before installation.

Incorrect oil level Adjust the engine oil level to the specified level.

Incorrect oil viscosity (high) Change to recommended engine oil.

Deteriorated oil Change to recommended engine oil.

TROUBLESHOOTING

9-7

EAM30511

TROUBLESHOOTING OF TRANSMISSION

Clutch noise

Damaged or worn primary driven gear

Replace the primary drive gear or crankshaft, and the clutch housing as a set.

Loose clutch boss nut Tighten the clutch boss nut to the specified torque.

Fatigued clutch damper Replace the clutch housing.

Worn clutch housing bearing Replace the clutch housing bear-ing.

Worn pressure plate bearing Replace the pressure plate bear-ing.


Difficult or impossible to shift transmission gear

Clutch drags Refer to “Clutch drags”.

Improperly adjusted shift rod Adjust the shift rod installation length.

Bent shift shaft Replace the shift shaft.

Foreign object in a shift drum groove

Remove foreign object from shift drum groove.

Damaged shift drum Replace the shift drum.

Seized shift fork Replace the shift fork and shift fork guide bar as a set.

Bent shift fork guide bar Replace the shift fork guide bar.

Foreign object between transmis-sion gears

Remove foreign object from trans-mission gears.

Seized transmission gear Replace the seized gear and the axle as a set.

Improperly assembled transmis-sion

Reassemble the transmission axle assembly.

Jumps out of gear

Incorrect shift pedal position Adjust the shift pedal position.

Improperly returned stopper lever Replace the stopper lever spring.

Bent or worn shift fork Replace the shift fork.

Shift drum incorrect axial play Replace the shift drum.

Worn shift drum groove Replace the shift drum.

Worn transmission gear dog Replace the transmission gear.

Transmission noise

Damaged or worn transmission gear Replace the transmission gear.

Worn main axle spline Replace the main axle.

Worn drive axle spline Replace the drive axle.

Worn bearing Replace the bearing.


TROUBLESHOOTING

9-8

EAM30512

TROUBLESHOOTING OF COOLING SYSTEM


Overheating

Carbon buildup in piston head and combustion chamber

Clean the piston head and com-bustion chamber.

Clogged engine cooling water passages

Check and clean the engine cool-ing water passages.

Damaged or leaking radiator Replace the radiator.

Faulty radiator cap Replace the radiator cap.

Clogged radiator fin Clean the radiator fin.

Bent or damaged radiator fin Repair the radiator fin or replace the radiator.

Damaged or faulty water pump Replace the water pump.

Damaged hoses or pipes Replace the hose or pipe.

Improperly connected hoses or pipes

Connect the hoses and pipes properly.


Brake dragsCheck the brake system and repair or replace faulty parts as necessary.

Incorrect spark plug gap Adjust to the specified spark plug gap.

Incorrect spark plug heat range Replace the spark plug with the one of the specified type.

Noise from water pump

Contact between the water pump housing cover and impeller

Disassemble the water pump and replace faulty parts.

Worn water pump housing bearing Replace the water pump housing bearing.

TROUBLESHOOTING

9-9

EAM30513

TROUBLESHOOTING OF BRAKE

EAM30514

TROUBLESHOOTING OF SUSPENSION


Poor performance of disc brake

Worn brake pad Replace the brake pads as a set.

Worn or deflected brake disc Replace the brake disc.

Air in hydraulic brake system Bleed the hydraulic brake system.

Brake fluid leakageCheck the hydraulic brake system and repair or replace faulty parts as necessary.

Incorrect brake fluid level (low) Add brake fluid to the specified level.

Stuck brake caliper piston Replace the caliper piston seal.

Stuck brake caliper and slide pin Lubricate the caliper slide pin.

Loose union bolt Tighten the union bolt to the speci-fied torque.

Damaged brake hose and brake pipe

Replace the brake hose and brake pipe.

Oil or grease on the brake disc or brake pad Clean the brake disc or brake pad.

Insufficient lubrication of brake lever or brake pedal pivot

Lubricate the brake lever or brake pedal pivot.


Front fork is hard

Bent or damaged inner tube Replace the inner tube.

Bent or damaged outer tube Replace the outer tube.

Damaged or worn slide metal Replace the slide metal.

Bent or damaged damper rod Replace the damper rod.

Bent wheel axle Replace the wheel axle.

Incorrect oil viscosity (high) Change to recommended fork oil.

Incorrect oil level (high) Adjust to the specified oil level.

Improperly adjusted spring pre-load (hard) Adjust the spring preload.

Improperly adjusted rebound damping (hard) Adjust the rebound damping.

Improperly adjusted compression damping (hard) Adjust the compression damping.

TROUBLESHOOTING

9-10

Front fork is soft

Fatigued or broken fork spring Replace the fork spring.

Incorrect oil viscosity (low) Change to recommended fork oil.

Incorrect oil level (low) Adjust to the specified oil level.

Improperly adjusted spring pre-load (soft) Adjust the spring preload.

Improperly adjusted rebound damping (soft) Adjust the rebound damping.

Improperly adjusted compression damping (soft) Adjust the compression damping.

Leaking oil from front fork

Bent, damaged, or corroded inner tube Replace the inner tube.

Cracked or damaged outer tube Replace the outer tube.

Improperly installed oil seal Replace the oil seal.

Damaged oil seal lip Replace the oil seal.

Incorrect oil level (high) Adjust to the specified oil level.

Loose damper rod assembly bolt Tighten the damper rod assembly bolt to the specified torque.

Damaged damper rod assembly bolt copper washer

Replace the damper rod assembly bolt copper washer.

Cracked or damaged cap bolt O-ring Replace the cap bolt O-ring.

Rear suspension is hard

Bent or damaged rear shock absorber rod Replace the rear shock absorber.

Bent swingarm pivot shaft Replace the swingarm pivot shaft.

Damaged or worn swingarm bear-ing or bushing

Replace the swingarm bearing or bushing.

Damaged or worn relay arm bear-ing Replace the relay arm bearing.

Damaged or worn connecting arm bearing

Replace the connecting arm bear-ing.

Improperly adjusted rear shock absorber spring preload (hard) Adjust the spring preload.

Improperly adjusted rear shock absorber rebound damping (hard) Adjust the rebound damping.

Improperly adjusted rear shock absorber compression damping (hard)

Adjust the compression damping.


TROUBLESHOOTING

9-11

EAM30515

TROUBLESHOOTING OF STEERING/HANDLING

Rear suspension is soft

Oil leaking from rear shock absorber Replace the rear shock absorber.

Gas leaking from rear shock absorber Replace the rear shock absorber.

Fatigued or damaged rear shock absorber spring Replace the rear shock absorber.

Improperly adjusted rear shock absorber spring preload (soft) Adjust the spring preload.

Improperly adjusted rear shock absorber rebound damping (soft) Adjust the rebound damping.

Improperly adjusted rear shock absorber compression damping (soft)

Adjust the compression damping.

Oil leaking from rear shock absorber

Bent, damaged, or corroded rear shock absorber rod Replace the rear shock absorber.

Damaged oil seal lip Replace the rear shock absorber.


Handlebar wobble

Loose steering ring nut Tighten the steering ring nut to the specified torque.

Worn bearing or bearing race Replace the bearing and bearing race as a set.

Warped front fork Repair or replace the front fork.

Bent front wheel axle Replace the front wheel axle.

Incorrect tire pressure Adjust to the specified tire pres-sure.

Worn, deformed, or incorrect tire Replace the tire.

Heavy steering

Steering ring nut is tightened too tight.

Tighten the steering ring nut to the specified torque.

Bent lower bracket Replace the lower bracket.

Broken bearing or bearing race Replace the bearing and bearing race as a set.

Incorrect tire pressure Adjust to the specified tire pres-sure.


TROUBLESHOOTING

9-12

Front wheel vibration

Incorrect wheel balance Adjust the wheel balance.

Loose spoke Tighten the spoke and adjust the runout.

Damaged or worn wheel bearing Replace the wheel bearing.


Loose wheel axle or wheel axle nut

Tighten the wheel axle or wheel axle nut to the specified torque.

Loose wheel axle pinch bolt Tighten the wheel axle pinch bolt to the specified torque.

Incorrect front fork oil level Adjust to the specified front fork oil level.

Rear wheel vibration

Incorrect wheel balance Adjust the wheel balance.

Loose spoke Tighten the spoke and adjust the runout.

Damaged or worn wheel bearing Replace the wheel bearing.


Loose wheel axle nut Tighten the wheel axle nut to the specified torque.

Loose swingarm pivot shaft Tighten the swingarm pivot shaft to the specified torque.

Bent or damaged swingarm Replace the swingarm bearing.

Damaged or worn swingarm bear-ing or bushing

Replace the swingarm bearing or bushing.


TROUBLESHOOTING

9-13

1

2

3

4

5

6

7

8

9

10

TUNING

ENGINE...........................................................................................................10-1CARBURETOR SETTING ........................................................................10-1ATMOSPHERIC CONDITIONS AND CARBURETOR SETTINGS ..........10-1TEST RUN................................................................................................10-1EFFECTS OF THE SETTING PARTS ON THE THROTTLE VALVE OPENING ................................................................................................10-2MAIN JET ADJUSTMENT ........................................................................10-2PILOT AIR SCREW ADJUSTMENT.........................................................10-2PILOT JET ADJUSTMENT.......................................................................10-2JET NEEDLE ADJUSTMENT...................................................................10-3JET NEEDLE GROOVE POSITION ADJUSTMENT................................10-3RELATIONSHIP WITH THROTTLE OPENING........................................10-3CARBURETOR SETTING PARTS ...........................................................10-4ROAD CONDITION AND EXAMPLES OF CARBURETOR SETTING.....10-5SPECIFICATIONS OF JET NEEDLE .......................................................10-5EXAMPLES OF CARBURETOR SETTING DEPENDING ON SYMPTOM...............................................................................................10-5CHANGE OF THE HEAT RANGE OF SPARK PLUGS............................10-7

CHASSIS ........................................................................................................10-8SELECTION OF THE SECONDARY REDUCTION RATIO (SPROCKET)...........................................................................................10-8DRIVE AND REAR WHEEL SPROCKETS SETTING PARTS.................10-8TIRE PRESSURE.....................................................................................10-8FRONT FORK SETTING..........................................................................10-9CHANGE IN AMOUNT AND CHARACTERISTICS OF FORK OIL ..........10-9SETTING OF SPRING AFTER REPLACEMENT.....................................10-9FRONT FORK SETTING PARTS...........................................................10-10REAR SUSPENSION SETTING.............................................................10-10CHOOSING SET LENGTH.....................................................................10-10SETTING OF SPRING AFTER REPLACEMENT...................................10-11REAR SHOCK ABSORBER SETTING PARTS .....................................10-11SUSPENSION SETTING (FRONT FORK).............................................10-13SUSPENSION SETTING (REAR SHOCK ABSORBER)........................10-14

ENGINE

10-1

EAM20198

ENGINEEAM30590

CARBURETOR SETTING• The role of fuel is to cool the engine, and in the

case of a 2-stroke engine, to lubricate the en-gine in addition to power generation. Accord-ingly, if a mixture of air and fuel is too lean,abnormal combustion will occur, and engineseizure may result. If the mixture is too rich,spark plugs will get wet with oil, thus making itimpossible to bring the engine into full play or ifthe worst comes to the worst, the engine maystall.

• The richness of the air-fuel mixture required forthe engine will vary with atmospheric condi-tions of the day and therefore, the settings ofthe carburetor must be properly suited to theatmospheric conditions (air pressure, humidityand temperature).

• Finally, the rider himself must make a test runand check his vehicle for conditions (pick-up ofengine speed, road surface conditions) and forthe discoloration of the spark plug(s).After taking these into consideration, he mustselect the best possible carburetor settings.

TIPIt is advisable to make a note of settings, atmo-spheric conditions, road surface condition, lap-time, etc. so that the memorandum can be usedas a reference useful for future.

EAM30591

ATMOSPHERIC CONDITIONS AND CARBURETOR SETTINGS

The air density (i.e., concentration of oxygen inthe air) determines the richness or leanness ofthe air/fuel mixture. Therefore, refer to the abovetable for mixture settings.That is:• Higher temperature expands the air with its re-

sultant reduced density.• Higher humidity reduces the amount of oxygen

in the air by so much of the water vapor in thesame air.

• Lower atmospheric pressure (at a high alti-tude) reduces the density of the air.

EAM30592

TEST RUNAfter warming up the engine equipped with thestandard type carburetor(s) and spark plug(s),run two or three laps of the circuit and check thesmooth operation of the engine and discolor-ation of spark plug(s).

Air temp. Humidity

Air pres-sure (alti-tude)

Mixture Setting

High High Low (high) Richer Leaner

Low Low High (low) Leaner Richer

Discoloration Condition of spark plug

Normal Insulator is dry and burnt brown.

Over burned (too lean) Insulator is whitish.

Oil fouled (too rich) Insulator is sooty and wet.

A. NormalB. Over burned (too lean)C. Oil fouled (too rich)

A

B

C

ENGINE

10-2

EAM30593

EFFECTS OF THE SETTING PARTS ON THE THROTTLE VALVE OPENING

EAM30594

MAIN JET ADJUSTMENTThe richness of air-fuel mixture with 1/2–4/4throttle can be set by changing the main jet “1”.

1. Spark plug is too hot.Select a main jet having higher calibratingNo. than standard. (To be enriched)

2. Spark plug is wet.Select a main jet having lower calibrating No.than standard. (To be leaned out)

EAM30595

PILOT AIR SCREW ADJUSTMENTThe richness of the air-fuel mixture with thethrottle fully closed to 1/4 open can be set byturning the pilot air screw “1”.Turning in the pilot air screw will make the mix-ture enrich at low speeds, and turning it out willlean it.

EAM30596

PILOT JET ADJUSTMENTThe richness of air-fuel mixture with the throttlefully closed to 1/2 open can be set by turning thepilot jet “1”. It is changed when adjustment can-not be made by the pilot air screw alone.A larger size jet results in a richer mixture at lowspeeds, and a smaller size in a leaner mixture.

A. ClosedB. Full-open

1. Pilot air screw2. Pilot jet3. Jet needle4. Diameter of straight portion5. Clip position6. Throttle valve7. Main jet

Standard main jet #430

Standard pilot air screw position 2-1/4 turns out

Standard pilot jet #40

ENGINE

10-3

EAM30597

JET NEEDLE ADJUSTMENTOn the carburetors used in the YZ125X the mainnozzle is a non disassembly type, so it can notbe replaced. Therefore, carburetor setting re-quires the change of the jet needle.1. The jet needle setting parts, having the same

taper angle, are available in different straightportion diameters and in different taper start-ing positions.

In the case of the same number of clip posi-tion, changing from 6BFY43-74 to 6BFY42-74 has the same effect as a lowering of 0.5-clip position. And in the case of the samenumber of clip position, changing from6BFY43-74 to 6BFY44-74 has the same ef-fect as a rising of 0.5-clip position.

EAM30598

JET NEEDLE GROOVE POSITION ADJUSTMENTShould the engine be hard to run smoothly at in-termediate speeds, the jet needle “1” must beadjusted. If the mixture is too rich or too lean atintermediate speed operation, irregular engine

operation and poor acceleration will result.Whether or not the richness of the mixture isproper is hard to be determined by means of thespark plug and therefore, it should be judgedfrom your feeling of actual engine operation.

1. Too rich at intermediate speedsRough engine operation is felt and the enginewill not pick up speed smoothly.In this case, step up the jet needle clip by onegroove or 0.5 groove and move down theneedle to lean out the mixture.

2. Too lean at intermediate speedsThe engine breathes hard and will not pick upspeed quickly.In this case, step down the jet needle clip byone groove or 0.5 groove and move up theneedle to enrich the mixture.

EAM30605

RELATIONSHIP WITH THROTTLE OPENINGThe flow of the fuel through the carburetor mainsystem is controlled by the main jet and then, itis further regulated by the area between themain nozzle and the jet needle. On the relation-ship between the fuel flow and the throttle open-ing, the fuel flow relates to the jet needle straightportion diameter around 1/8 to 1/4 throttle open-ing, whereas around 1/4 to 1/1 throttle opening itrelates to the taper starting position and to theclip position.Therefore, the fuel flow is balanced at eachstage of throttle opening by the combination ofthe jet needle straight portion diameter, taperstarting position and clip position.

Standard jet needle 6BFY43-74

A. Difference in straight portion diameterB. Difference in clip position

a. Reference needleb. Richc. Lean

6BFY43-73

6BFY43-72

6BFY43-74

6BFY43-75

6BFY43-76

6BFY44-74

6BFY43-74

6BFY42-74

Standard clip position No. 3 groove

1

ENGINE

10-4

Example:

EAM30599

CARBURETOR SETTING PARTS

A. Lean (larger diameter)B. Rich (smaller diameter)C. 1st taperD. 2nd taperE. 3rd taperF. 4th taper

1. Full closed2. 1/4 throttle3. 1/2 throttle4. 3/4 throttle5. Full open

a. Main nozzle

Part name Size Part number

Main jet Rich #470 137-14143-94

#460 137-14143-92

#450 137-14143-90

#440 137-14143-88

(STD) #430 137-14143-86

#420 137-14143-84

#410 137-14143-82

Lean #400 137-14143-80

6BFY43-74-36BFY43-74-26BFY43-75-3

Pilot jet Rich #50 4KM-14142-50

#47.5 4KM-14142-47

#45 4KM-14142-45

#42.5 4KM-14142-42

(STD) #40 4KM-14142-40

#37.5 4KM-14142-37

#35 4KM-14142-35

#32.5 4KM-14142-32

Lean #30 4KM-14142-30

Throttle valve

Rich

(STD) 4.0 1C3-14112-40

Lean 4.25 1C3-14112-42

Jet needle Rich 6BFY44-72 284-14116-K2

6BFY44-73 284-14116-K3

6BFY44-74 284-14116-K4

6BFY44-75 284-14116-K5

Lean 6BFY44-76 284-14116-K6

Rich 6BFY43-72 284-14116-J2

6BFY43-73 284-14116-J3

(STD) 6BFY43-74 284-14116-J4

6BFY43-75 284-14116-J5

Lean 6BFY43-76 284-14116-J6

Rich 6BFY42-72 284-14116-H2

6BFY42-73 284-14116-H3

6BFY42-74 284-14116-H4

6BFY42-75 284-14116-H5

Lean 6BFY42-76 284-14116-H6

Part name Size Part number

ENGINE

10-5

EAM30601

ROAD CONDITION AND EXAMPLES OF CARBURETOR SETTING

TIPOptimum pilot air screw setting can be obtained by adding the ex-factory number of the same screwback-out turns to any required value provided in the chart. For example, if the ex-factory number is “1”,add “1” to the value chosen in the chart.

EAM30600

SPECIFICATIONS OF JET NEEDLE

EAM30602

EXAMPLES OF CARBURETOR SETTING DEPENDING ON SYMPTOM

General condition Sandy condition

Under 10 C (50 F)

(Winter)

15–25 C (59–77 F) (Spring, Autumn)

Over 30 C (86 F)

(Summer)

Under 10 C (50 F)

(Winter)

15–25 C (59–77 F) (Spring, Autumn)

Over 30 C (86 F)

(Summer)

Main jet #440 #430 #420 #460 #450 #440

Jet needle 6BFY44-74-3 6BFY43-74-3 6BFY44-74-2 6BFY43-74-4 6BFY44-74-3 6BFY43-74-3

Pilot jet #42.5 #40 #37.5 #45 #42.5 #40

Pilot air screw 2-1/4 2-1/4 2-1/4 2-1/4 2-1/4 2-1/4

Diameter of straight portion

ø2.72 mm (0.1071 in)

ø2.73 mm (0.1075 in)

ø2.74 mm (0.1079 in)

ø2.75 mm (0.1083 in)

ø2.76 mm (0.1087 in)

Rich 1 richer 6BFY43-72-4 6BFY43-73-4 6BFY43-74-4 6BFY43-75-4 6BFY43-76-4

0.5 richer6BFY44-72-3 6BFY44-73-3 6BFY44-74-3 6BFY44-75-3 6BFY44-76-3

6BFY42-72-4 6BFY42-73-4 6BFY42-74-4 6BFY42-75-4 6BFY42-76-4

STD 6BFY43-72-3 6BFY43-73-3 6BFY43-74-3 6BFY43-75-3 6BFY43-76-3

0.5 leaner6BFY44-72-2 6BFY44-73-2 6BFY44-74-2 6BFY44-75-2 6BFY44-76-2

6BFY42-72-3 6BFY42-73-3 6BFY42-74-3 6BFY42-75-3 6BFY42-76-3

Lean 1 leaner 6BFY43-72-2 6BFY43-73-2 6BFY43-74-2 6BFY43-75-2 6BFY43-76-2

Symptom Setting Checking

• At full throttleStall at high speeds*Hard breathingShearing noiseWhitish spark plugLean mixture

Increase main jet calibration no. (Gradually)

• Discoloration of spark plug If tan color, it is in good condition.

• If cannot be corrected:Clogged float valve seatClogged fuel hoseClogged fuel cock

• At full throttleSpeed pick-up stopsSlow speed pick-upSlow responseSooty spark plugRich mixture

Decrease main jet calibration no. (Gradually)*In case of racing slight enrichment of mixture reduces engine trouble.

• Discoloration of spark plug If tan color, it is in good condition.

• If cannot be corrected:Clogged air filterFuel overflow from carburetorClogged main air passage or clogged filter

ENGINE

10-6

*marked: In case of hard breathing, check the carburetor breather hoses for clogging.This should be taken simply for an example. It is necessary to set the carburetor while checking theoperating conditions of the engine and discoloration of spark plugs.Normally, carburetor setting is made by means of the main jet, jet needle clip position (including onewith 0.5 difference), pilot jet and pilot air screw. It the result of setting is still unsatisfactory, it is advisableto change the diameter of the straight portion of the jet needle.

Lean mixture Lower jet needle clip position. (1 groove down)

1. Groove 12. Groove 23. Groove 34. Groove 45. Groove 56. Jet needle7. Clip

Leaner

(Standard)

Richer

Rich mixture Raise jet needle clip position. (1 groove up)

• 1/4–3/4 throttle*Hard breathingLack of speed

Lower jet needle clip position. (1 groove down)

• 1/4–1/2 throttleSlow speed pick-upWhite smokePoor acceleration Raise jet needle clip position. (1

groove up)

The clip position is the jet needle groove on which the clip is installed. The positions are numbered from the top.It a change in the clip position (1 groove) is effective, try another jet needle that provides a difference of 0.5 in the clip position.

• Closed to 1/4 throttle*Hard breathingSpeed down

Use jet needle having a smaller diam-eter.

• Closed to 1/4 throttlePoor accelerationWhite smoke

Use jet needle with a larger diameter.

• Unstable at low speedsPinking noise

Lower jet needle clip position. (1 groove down)Turn in pilot air screw.

Poor response at extremely low speed

Reduce pilot jet calibration No.Turn out pilot air screw.If not effect, reverse the above proce-dures.

Dragging brakeOverflow from carburetor

Poor response in the low to intermediate speeds

Raise jet needle clip position.If no effect, reverse the above proce-dures.

Poor response when throt-tle is opened quickly

Check overall settings.Use main jet having lower calibration No.Raise jet needle clip position. (1 groove up)If no effect, reverse the above proce-dures.

Check air filter for fouling.

Poor engine operation Turn in pilot air screw. Check throttle valve operation.

Symptom Setting Checking

ENGINE

10-7

EAM30603

CHANGE OF THE HEAT RANGE OF SPARK PLUGSJudging from the discoloration of spark plugs, ifthey are found improper, it can be corrected bythe following two methods; changing carburetorsettings and changing the heat range of sparkplug.

• In principle, it is advisable to first use sparkplugs of standard heat range, and judging fromthe discoloration of spark plugs, adjust carbu-retor settings.

• If the calibration No. of the main jet must bechanged by ±30, it is advisable to change theheat range of spark plugs and newly select theproper main jet.

TIP• When checking the discoloration of spark

plugs, be sure to stop the engine immediatelyafter a run and check.

• Avoid racing.• When changing the heat range of spark plugs,

never attempt to change it more than ±1 rank.• When using a spark plug other than standard,

check its heat range against the standard andcheck that it is a resistance type.

• Note that even if the discoloration seems prop-er, it may slightly vary with the spark plug mak-er and oil in use.

Standard spark plug BR9EVX(resistance type)

CHASSIS

10-8

EAM20119

CHASSISEAM30168

SELECTION OF THE SECONDARY REDUCTION RATIO (SPROCKET)

<Requirement for selection of secondary gearreduction ratio>• It is generally said that the secondary gear ratio

should be reduced for a longer straight portionof a speed course and should be increased fora course with many corners. Actually, howev-er, as the speed depends on the ground condi-tion of the day of the race, be sure to runthrough the circuit to set the machine suitablefor the entire course.

• In actuality, it is very difficult to achieve settingssuitable for the entire course and some set-tings may be sacrificed. Thus, the settingsshould be matched to the portion of the coursethat has the greatest effect on the race result.In such a case, run through the entire coursewhile making notes of lap times to find the bestbalance; then, determine the secondary reduc-tion ratio.

• If a course has a long straight portion where amachine can run at maximum speed, the ma-chine is generally set such that it can developits maximum revolutions toward the end of thestraight line, with care taken to avoid the en-gine over-revving.

TIPRiding technique varies from rider to rider andthe performance of a machine also vary frommachine to machine. Therefore, do not imitateother rider’s settings from the beginning butchoose your own setting according to the level ofyour riding technique.

EAM30169

DRIVE AND REAR WHEEL SPROCKETS SETTING PARTS

EAM30170

TIRE PRESSURETire pressure should be adjusted to suit the roadsurface condition of the circuit.

• Under a rainy, a muddy, a sandy, or a slipperycondition, the tire pressure should be lower fora larger area of contact with the road surface.

• Under a stony or a hard road condition, the tirepressure should be higher to prevent a flat tire.

Secondary reduction ratio = Number of rear wheel sprocket teeth/Number of drive sprocket teeth

Secondary reduction ratio3.846 (50/13)

Part name Type Part number

Drive sprocket “1” (STD) 13T 9383B-13218

Rear wheel sprocket “2”

47T 17D-25447-50

48T 17D-25448-50

49T 17D-25449-50

(STD) 50T 17D-25450-50

51T 17D-25451-50

52T 17D-25452-50

Standard tire pressure100 kPa (1.00 kgf/cm², 15 psi)

Extent of adjustment60–80 kPa (0.60–0.80 kgf/cm², 9–12 psi)

CHASSIS

10-9

EAM30171

FRONT FORK SETTINGThe front fork setting should be made dependingon the rider’s feeling of an actual run and the cir-cuit conditions.The front fork setting includes the following threefactors:1. Setting of air spring characteristics

• Change the fork oil amount.2. Setting of spring preload

• Change the spring.3. Setting of damping force

• Change the compression damping force.• Change the rebound damping force.

The spring acts on the load and the dampingforce acts on the cushion travel speed.

EAM30172

CHANGE IN AMOUNT AND CHARACTERISTICS OF FORK OILDamping characteristic near the final stroke canbe changed by changing the fork oil amount.

WARNINGEWA19190

Adjust the oil amount in 5 cm³ (0.2 US oz, 0.2Imp.oz) increments or decrements. Toosmall oil amount causes the front fork to pro-duce a noise at full rebound or the rider tofeel some pressure on his hands or body. Al-ternatively, too large oil amount will causethe air spring characteristics to have a ten-dency to be stiffer with the consequent dete-riorated performance and characteristics.Therefore, adjust the front fork within thespecified range.

EAM30173

SETTING OF SPRING AFTER REPLACEMENTAs the front fork setting can be easily affected bythe rear suspension, take care so that the frontand the rear are balanced (in position etc.) whensetting the front fork.1. Use of soft spring

• Change the rebound damping force.Turn out one or two clicks.

• Change the compression damping force.Turn in one or two clicks.

TIPGenerally a soft spring gives a soft riding feeling.Rebound damping tends to become strongerand the front fork may sink deeply over a seriesof gaps.

2. Use of stiff spring• Change the rebound damping force.

Turn in one or two clicks.• Change the compression damping force.

Turn out one or two clicks.

Extent of adjustment100–120 kPa (1.00–1.20 kgf/cm², 15–18 psi)



Extent of adjustment210–365 cm³ (7.1–12.3 US oz, 7.4–12.9 Imp.oz)

A. Air spring characteristics in relation to oil amount change

B. LoadC. Stroke

1. Max. oil amount2. Standard oil amount3. Min. oil amount

CHASSIS

10-10

TIPGenerally a stiff spring gives a stiff riding feeling.Rebound damping tends to become weaker, re-sulting in lack of a sense of contact with the roadsurface or in a vibrating handlebar.

EAM30174

FRONT FORK SETTING PARTS• Front fork spring “1”

TIPThe I.D. mark (slits) “a” is proved on the end ofthe spring.

EAM30175

REAR SUSPENSION SETTINGThe rear shock absorber setting should be madedepending on the rider’s feeling of an actual runand the circuit conditions.The rear suspension setting includes the follow-ing two factors:1. Setting of spring preload

• Change the set length of the spring.• Change the spring.

2. Setting of damping force• Change the rebound damping force.• Change the compression damping force.

EAM30176

CHOOSING SET LENGTH1. Place a stand or a block under the engine to

put the rear wheel above the floor, and mea-sure the length “a” between the rear wheelaxle center and the rear fender holding bolt.

2. Remove the stand or block from the engineand, with a rider astride the seat, measure thesunken length “b” between the rear wheelaxle center and the rear fender holding bolt.

3. Loosen the locknut “1” and make adjustmentby turning the adjuster “2” to achieve thestandard figure from the subtraction of thelength “b” from the length “a”.

TIP• If the machine is new and after it is broken in,

STD spring rate(N/mm) 4.1

TypeSpring

rate (N/mm)

Part numberI.D.

mark (slits)

SOFT 3.9 1C3-23141-A1 I

4.0 1C3-23141-B1 II

4.1 1C3-23141-C1 III

4.2 1C3-23141-D1 IIII

4.3 1C3-23141-E1 IIIII

4.4 1C3-23141-F1 I-I

4.5 1C3-23141-G1 I-II

4.6 1C3-23141-H1 I-III

STIFF 4.7 1C3-23141-J1 I-IIII

a

1

Standard figure90–100 mm (3.5–3.9 in)

CHASSIS

10-11

the same set length of the spring may changebecause of the initial fatigue, etc. of the spring.Therefore, be sure to make reevaluation.

• If the standard figure cannot be achieved byadjusting the adjuster and changing the setlength, replace the spring with an optional oneand make readjustment.

EAM30177

SETTING OF SPRING AFTER REPLACEMENTAfter replacement, be sure to adjust the spring tothe set length [sunken length 90–100 mm (3.5–3.9 in)] and set it.1. Use of soft spring

• Adjust to decrease rebound damping force tocompensate for less spring load. Run with therebound damping force adjuster one or twoclicks turned out, and readjust it to suit yourpreference.

2. Use of stiff spring• Adjust to increase rebound damping force to

compensate for greater spring load. Run withthe rebound damping force adjuster one ortwo clicks turned in, and readjust it to suit yourpreference.

TIPAdjusting the rebound damping force will be fol-lowed more or less by a change in the compres-sion damping force. For correction, adjust todecrease compression damping force.

WARNINGEWA19200

When using a rear shock absorber otherthan currently installed, use the one whoseoverall length “a” does not exceed the stan-dard as it may result in faulty performance.Never use one whose overall length is great-er than standard.

EAM30178

REAR SHOCK ABSORBER SETTING PARTS• Rear shock spring “1”[Equal-pitch steel spring]

[Unequal-pitch steel spring]

TIP• The unequal-pitch spring is softer in initial char-

acteristic than the equal-pitch spring and is dif-ficult to bottom out under full compression.

• The I.D. mark “a” is marked at the end of thespring.

• Spring specification varies according to the

Length “a” of standard shock490 mm (19.29 in)

STD spring rate(N/mm) 46

TypeSpring

rate (N/mm)

Part number I.D. mark/Q’ty

SOFT 42 5UN-22212-00 Brown/1

44 5UN-22212-10 Green/1

46 5UN-22212-20 Red/1

48 5UN-22212-30 Black/1

50 5UN-22212-40 Blue/1

52 5UN-22212-50 Yellow/1

54 5UN-22212-60 Pink/1

STIFF 56 5UN-22212-70 White/1

TypeSpring

rate (N/mm)

Part number I.D. mark/Q’ty

SOFT 44 5UN-22212-A0 Green/2

46 5UN-22212-B0 Red/2

48 5UN-22212-C0 Black/2

50 5UN-22212-D0 Blue/2

52 5UN-22212-E0 Yellow/2

54 5UN-22212-F0 Pink/2

STIFF 56 5UN-22212-G0 White/2

CHASSIS

10-12

color and quantity of I.D. marks.

• Spring preload adjusting positions

TIPFor the spring preload adjustment, refer to “AD-JUSTING THE REAR SHOCK ABSORBER AS-SEMBLY” on page 3-21.

Spring preload adjusting positionsMinimum

Position in which the spring is turned in 1.5 mm (0.06 in) from its free length.

StandardPosition in which the spring is turned in 6.0 mm (0.24 in) from its free length.

MaximumPosition in which the spring is turned in 18.0 mm (0.71 in) from its free length.

CHASSIS

10-13

EAM30179

SUSPENSION SETTING (FRONT FORK)TIP• If any of the following symptoms is experienced with the standard position as the base, make resetting

by reference to the adjustment procedure given in the same chart.• Before any change, set the rear shock absorber sunken length to the standard figure 90–100 mm

(3.5–3.9 in).

Symptom

Section

Check AdjustJump Large

gapMedium

gapSmall gap

Stiff over entire range

Compression damping force

Turn adjuster counterclockwise (about 2 clicks) to decrease damping.

Oil amountDecrease oil amount by about 5–10 cm³ (0.2–0.3 US oz, 0.2–0.4 Imp.oz).

Spring Replace with soft spring.

Unsmooth move-ment over entire range

Outer tubeInner tube

Check for any bends, dents, other noticeable scars, etc. If any, replace affected parts.

Slide metal Replace with a new one for extended use.

Piston metal Replace with a new one for extended use.

Lower bracket tightening torque Retighten to specified torque.

Poor initial move-ment

Rebound damp-ing force


Oil seals Apply grease in oil seal wall.

Soft over entire range, bottoming out


Turn adjuster clockwise (about 2 clicks) to increase damping.

Oil amountIncrease oil amount by about 5–10 cm³ (0.2–0.3 US oz, 0.2–0.4 Imp.oz).

Spring Replace with stiff spring.

Stiff toward stroke end Oil amount Decrease oil amount by about 5

cm³ (0.2 US oz, 0.2 Imp.oz).

Soft toward stroke end, bot-toming out

Oil amount Increase oil amount by about 5 cm³ (0.2 US oz, 0.2 Imp.oz).

Stiff initial move-ment Compression

damping force


CHASSIS

10-14

EAM30180

SUSPENSION SETTING (REAR SHOCK ABSORBER)TIP• If any of the following symptoms is experienced with the standard position as the base, make resetting

by reference to the adjustment procedure given in the same chart.• Adjust the rebound damping in 2-click increments or decrements.• Adjust the low compression damping in 1-click increments or decrements.• Adjust the high compression damping in 1/6 turn increments or decrements.

Low front, tend-ing to lower front posture





Balance with rear end

Set sunken length for 95–100 mm (3.7–3.9 in) when one pas-senger is astride seat (lower rear posture).

Oil amount Increase oil amount by about 5 cm³ (0.2 US oz, 0.2 Imp.oz).

“Obtrusive” front, tending to upper front posture



Balance with rear end

Set sunken length for 90–95 mm (3.5–3.7 in) when one passenger is astride seat (upper rear pos-ture).


Oil amountDecrease oil amount by about 5–10 cm³ (0.2–0.3 US oz, 0.2–0.4 Imp.oz).

Symptom

Section


gapMedium

gapSmall gap

Stiff, tending to sink



Spring set lengthSet sunken length for 90–100 mm (3.5–3.9 in) when one pas-senger is astride seat.

Spongy and unstable



Low compres-sion damping

Turn adjuster clockwise (about 1 click) to increase damping.


Symptom

Section


gapMedium

gapSmall gap

CHASSIS

10-15

Heavy and drag-ging




Poor road grip-ping



Low compres-sion damping

Turn adjuster clockwise (about 1 click) to increase damping.

High compres-sion damping

Turn adjuster clockwise (about 1/6 turn) to increase damping.



Bottoming out


Turn adjuster clockwise (about 1/6 turn) to increase damping.



Bouncing Rebound damp-ing force



Stiff travel


Turn adjuster counterclockwise (about 1/6 turn) to decrease damping.



Symptom

Section


gapMedium

gapSmall gap

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OWNER’S SERVICE MANUAL…Read this manual carefully before operating this vehicle. 2021 OWNER’S...

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