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R
T
1
A
7
4
LI
T
11
61
6
07
3
5
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T
100A
SERVICE MANUAL
1990
by
Yamaha
Motor
Corporation U.S.A.
1st Edition January 1990
All rights reserved. Any reprinting or
unauthorized use without the
written
permission
of
Yamaha
Motor
Corporation
U.S.A. is expressly
prohibited.
Printed in U.S.A.
P/N: LIT-11616-07-35
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NOTICE
This manual
was
by
the
Yamaha
Motor Company
primary for use
by
Yamaha dealers and
their
qualified
mechanics. It
is
not
possible
to
put
n
entire mechanic's education
into
one manual, so
it
is assumed
that
person using
this
book
to
perform
maintenance
and
repairs
on Yamaha ma-
chines have a basic understanding of the mechanical concepts and procedures inherent in ma-
chine
repair technology. Without
such
knowledge, attempt repairs
or service
to this
model
may
render
it
unfit
to
use
and/or unsafe.
Yamaha
Motor Company, Ltd.
is continually striving
to improve
all models manufactured by
Yamaha.
Modifications
and significant changes in specifications or procedures will be
forwarded
to
all Authorized Yamaha dealers and will, there applicable, appear in future editions of
this
manual.
TECHNICAL PUBLICATIONS
SERVICE DIVISION
MOTORCYCLEGROUP
Y M H
MOTOR CO. L TO.
PARTICULARLY IMPORT
NT
INFORMATION
This
material is distinguished by
the
following notation.
A WARNING
CAUTIO .:
NOTE:
The Safety Alert Symbol
means
ATTENTION
BECOME ALERT YOUR
SAFETY IS INVOLVED
Failure to follow WARNING
instructions
could result in severe injury or
death to
the
machine operator, a
bystander, or
a person inspecting
or
re-
pairing the machine.
A
CAUTION indicates
special precautions that
must
be taken to
avoid
damage to
the
machine.
A NOTE provides key
information
to
make procedures
easier or clearer.
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HOW
TO
USE THIS MANUAL
CONSTRACTION OF THIS MANUAL
This manual consists of chapters for
the
main categories of subjects. (See Illustrated symbols )
1st title
CD
:
2nd
title :
This
is a
chapter with
its
symbol
on
the
upper
right of
each page.
This
title appears
on
the
upper of each page on
the left of the
chapter
symbol. (For the chapter Periodic inspection and adjustment
the
3rd
title appears.)
3rd
title
@: This is a final
title.
MANUAL FORMAT
All of the procedures in
this
manual are organized in a sequential, step-by-step
format. The
infor
mation has been compiled to provide the
mechanic
with an easy to read, handy reference
that
contains
comprehensive
explanations
of all disassembly, repair, assembly, and
inspections.
A set of particularly important
procedure
C > is placed between a line of asterisks * with each
procedure
preceded
by
IMPORTANT FEATURES
Data and a special
tool
are framed in a box preceded by a relevant symbol .
An encircled
numeral
indicates a part name, and an encircled alphabetical
letter
data or an
alignment mark j) , the others being
indicated
by an alphabetical
letter
in a box .
A condition of a
faulty component will precede
an
arrow
symbol and
the course
of action re-
quired
the
symbol .
EXPLODED DIAGRAM
Each chapter provides exploded diagrams before each disassembly section
for
ease in identif
ying
correct
disassembly and assembly procedures.
2.,__.,
Crlftkt:Mtc
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D
~ ~ ~ ~
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_
@
a
IL
LUSTR TE
D SYMBO
LS
Re
fer to
th
i l lustration
)
Illustrated sym
bols G to
are designed as
thum
tabs to
indicate the cha
pte r s number a
nd
c
ontent .
D
General information
Sp
ecifications
I
er
iodic inspection
and adjustment
Engine
Cooling sy
stem
Carburetion
Q
Chassis
@ E
lectrical
Troubleshoo
ting
I
llustrated sym b
ols
to are
use d to ident i f
y
the specificatio
ns appearing i
n th e text.
I
illing fluid
L
ubricant
Specia
l tool
@
Tighteni
ng
@
Wear limit, clea
rance
Eng
ine speed
@ fl , V A
I l lustrated
s y mbols
to
@
in the explo
deddia-
gram ind
ic ate grade of
lubr icant and lo
cation of
lubr icat ion
point.
@
App ly engin
e oil
A
pply gear oil
A
pply molybdenu
m disulfide oil
Apply wheel bearing grease
Ap
ply l ightweight l i
thium-soap
base
grease
@
Apply mo
lybdenum disulfi
de grease
Apply lockin
g agent (LOCTIT
E)
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INDEX
GENERAL
INFORM TION
SPECIFICATIONS
PERIODIC INSPECTION
ND
DJUSTMENT
ENGINE
OVERH UL
CARBURETION
CH SSIS
ELECTRICAL
TROUBLESHOOTING
SPEC
NG
?
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CONTENTS
CHAPTER 1.
GENERAL INFORMATION
M CHINE
IDENTIFICATION -1
VEHICLE IDENTIFICATION NUMBER 1-1
ENGINE SERIAL NUMBER
1-1
IMPORT NT INFORMATION 1 2
PREPARATION FOR
REMOVAL AND DISASSEMBLY
1 2
ALL REPLACEMENT PARTS
1 3
GASKETS OIL SEALS
AND
0 RINGS
1 3
LOCK WASHERS/PLATE AND COTIER
PINS 1 3
BEARINGS
AND
OIL SEALS 1 3
CIRCLIPS
1 4
SPECIAL TOOLS 1 4
FOR
TUNE
UP
1 4
FOR
ENGINE
SERVICE 1-5
FOR CHASSIS SERVICE 1-6
FOR ELECTRICAL
COMPONENTS
1-6
CHAPTER2.
SPECIFICATIONS
GENERAL SPECIFICATIONS 2-1
MAINTENANCE SPECIFICATIONS 2 4
ENGINE
2 4
CHASSIS
;
2-8
ELECTRICAL
2-11
GENERAL TORQUE SPECIFICATIONS 2 12
DEFINITION OF UNITS 2 12
LUBRICATION POINTS
ND
LUBRICANT TYPE 2 13
ENGINE 2 13
CHASSIS 2 13
CABLE ROUTING 2 14
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CHAPTER3
PERIODIC INSPECTION
ND
ADJUSTMENT
INTRODUCTION 3 1
PERIODIC MAINTENANCE/LUBRICATION INTERVALS 3 1
ENGINE 3-2
IDLING SPEED
ADJUSTMENT 3-2
THROTTLE CABLE
ADJUSTMENT 3-3
AUTOLUBE
PUMP
CABLE
ADJUSTMENT 3-4
AUTOLUBE PUMP STROKE
ADJUSTMENT 3-4
AUTOLUBE PUMP AIR BLEEDING
3-6
SPARK
PLUG INSPECTION
3-8
IGNITION TIMING CHECK 3-9
ENGINE OIL LEVEL CHECK
3-10
TRANSMISSION
OIL
LEVEL INSPECTION 3-10
TRANSMISSION OIL REPLACEMENT 3-12
CLUTCH
ADJUSTMENT 3-12
AIR FILTER CLEANING
3-13
CARBURETOR JOINT INSPECTION 3-15
FUEL
LINE INSPECTION 3-15
EXHAUST
SYSTEM INSPECTION 3-15
CHASSIS
3-16
FRONT BRAKE
ADJUSTMENT 3-16
REAR BRAKE ADJUSTMENT 3-17
DRIVE
CHAIN
SLACK
ADJUSTMENT 3-17
DRIVE CHAIN
LUBRICATION
3-19
STEERING HEAD ADJUSTMENT 3-20
TIRE INSPECTION 3-22
WHEEL INSPECTION
3-24
SPOKES INSPECTION AND TIGHTENING 3-24
FRONT
FORK
INSPECTION 3-24
REAR SHOCK ABSORBER
ADJUSTMENT 3-25
CABLE
INSPECTION AND
LUBRICATION
3-25
LEVER
AND
PEDAL LUBRICATION
3-25
SIDESTAND LUBRICATION
3-26
G N
INFO
SPE
NG
ELE
?
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CHAPTER4
ENGINE OVERHAUL
ENGINE REMOVAL -1
TRANSMISSION OIL 4-1
SEAT
AND SIDE COVER 4-1
FUEL
TANK 4-2
MUFFLER 4-2
CARBURETOR 4-2
AUTOLUBE PUMP CABLE AND HOSE 4-3
LEADS
4-3
CLUTCH CABLE
4-3
DRIVE CHAIN 4-3
ENGINE REMOVAL. 4-4
ENGINE DISASSEMBLY 4-4
CYLINDER HEAD CYLINDER AND PISTON 4-4
CLUTCH
AND PRIMARY
DRIVE
GEAR. 4-6
KICK AXLE
4-7
SHIFT
SHAFT
4-8
COl
MAGNETO 4-9
CLUTCH
PUSH LEVER
4-10
CRANKCASE
4-10
TRANSMISSION
SHIFTER
AND CRANKSHAFT 4-11
INSPECTION ND REPAIR 4-12
CYLINDER HEAD 4-12
CYLINDER AND PISTON 4-13
PISTON RINGS
4-15
PISTON PIN AND BEARING 4-16
CLUTCH 4-17
PRIMARY DRIVE 4-19
KICK STARTER 4-20
SHIFT SHAFT 4-20
TRANSMISSION AND SHIFTER 4-20
CRANKSHAFT 4-22
CRANKCASE
4-23
AUTOLUBE PUMP 4-23
ENGINE ASSEMBLY
ND DJUSTMENT
4-25
CRANKSHAFT
SHIFTER
AND TRANSMISSION 4-28
CRANKCASE
4-29
CLUTCH
PUSH LEVER
4-30
COl
MAGNETO 4-30
SHIFT
SHAFT 4-32
KICK
AXLE 4-35
CLUTCH AND PRIMARY DRIVE GEAR 4-35
CYLINDER HEAD CYLINDER AND PISTON 4-38
REMOUNTING ENGINE
4-41
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CHAPTERS
CARBURETION
C RBURETOR 5 1
REMOVAL 5 2
DISASSEMBLY 5 2
INSPECTION 5 3
ASSEMBLY 5 5
INSTALLATION 5 6
ADJUSTMENT 5 7
REED
V LVE
5 9
REMOVAL 5 10
INSPECTION .. 5 10
INSTALLATION 5 11
SPEC
CHAPTERS
CHASSIS
FRONT WHEEL
6 1
REMOVAL 6 2
INSPECTION 6 2
INSTALLATION 6 5
0
RE R WHEEL 6 8
REMOVAL 6 9
NG
INSPECTION 6 10
INSTALLATION 6 10
FRONT FORK 6 12
REMOVAL 6 13
DISASSEMBLY 6 13
INSPECTION 6 14
ASSEMBLY 6 15
INSTALLATION 6 17
STEERING
HE D AND
H NDLEB R 6 18
REMOVAL 6 19
INSPECTION 6 20
INSTALLATION 6 21
RE R SHOCK BSORBER
AND SWINGARM
6 25
REMOVAL 6 26
INSPECTION 6 27
INSTALLATION 6 28
?
DRIVE CHAIN AND SPROCKETS 6 30
REMOVAL 6 31
INSPECTION 6 31
INSTALLATION 6 32
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CHAPTER7.
ELECTRICAL
IGNITION SYSTEM 7 1
TROUBLESHOOTING 7 3
CHAPTERS.
TROUBLESHOOTING
STARTING FAILURE/HARD STARTING 8 1
FUEL SYSTEM
8 1
ELECTRICAL SYSTEM
8 2
COMPRESSION SYSTEM
8 2
POOR IDLE SPEED PERFORMANCE 8 3
POOR IDLE SPEED PERFORMANCE 8 3
POOR MEDIUM ND HIGH SPEED PERFORMANCE 8 3
FUEL
SYSTEM
8 3
ELECTRICAL SYSTEM 8 3
COMPRESSION SYSTEM 8 4
FAULTV GEAR SHIFTING 8 4
HARD SHIFTING 8 4
CHANGE PEDAL
DOES NOT MOVE
8 5
JUMP OUT GEAR
8 5
CLUTCH SLIPPING/DRAGGING 8 5
CLUTCH
SLIPPING 8 5
CLUTCH DRAGGING
8 5
IMPROPER KICKING 8 6
SLIPPING 8 6
HARD KICKING 8 6
KICK CRANK NOT
RETURNING 8 6
FAULTV BRAKE 8 7
POOR
BRAKING EFFECT
8 7
FRONT FORK OIL LEAKAGE
ND
FRONT FORK M LFUNCTION 8 7
OIL
LEAKAGE
8 7
MALFUNCTION
8 7
INSTABLE
H NDLING
8 8
INSTABLE HANDLING 8 8
OVERHEATING 8 9
OVERHEATING
8 9
RT1
OOA WIRING DIAGRAM
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MACHINE IDENTIFICATION 1 ~ ~ ~
I
1 1
YB111001
GENERAL
INFORMATION
MACHINE IDENTIFICATION
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number D is stam
ped
into the
steering head pipe.
Starting serial number:
RT100A JYA3ULWO LC000101
NOTE
The vehicle identification number
is used
to
identify
your machine and may be used to re-
gister your machine with the licensing au-
thority in your state.
ENGINE SERIAL NUMBER
The engine serial number D is
stamped into
the left
of
the
engine
Starting serial number:
RT100A
.........
3UL-000101
NOTE
The
first
three
digits
of these numbers
are
for model
identifications; the
remaining
digits are
the
unit
production number.
Designs and
specifications
are
subject
to
change
without
notice.
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M _ P _ o _ R _ T _ N _ T _ I N _ F _ o _ R _ M _ _ T a _ o _ N _ I ~ ~ ~ ~ ~
YB112001
IMPORT NT INFORM TION
PREP R TION FOR REMOV L ND DIS S-
SEMBLY
1. Remove all
dirt
mud
dust
and foreign ma
terial before removing
and disassembling.
2. Use
proper tools
and cleaning equipment.
Refer
to
WSPECI L
TOOLw
3. When disassembling the machine keep
mated parts together. This
includes gears
cylinders pistons
and
other
mated
parts
that
have
been wm tedw
through
normal
wear. Mated parts
must
be reused as an
assembly or replaced.
4.
During
the
machine disassembly clean all
parts
and place
them
in
trays
in
the order
of disassembly.
This will
speed
up
assemb
ly time
and help assure
that
all
parts
are
correctly
reinstalled.
5. Keep
away from fire.
1-2
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I
IMPORTANT INFORMATION
I
~
I
300 000
300 003
1-3
YB112002
ALL REPLACEMENT PARTS
1.
We recommend
to use Yamaha genuine
parts for all
replacements.
Use oil
and/or
grease
recommended
by Yamaha for asse
mbly
and
adjustment.
YB112003
GASKETS, OIL SEALS,
AND
0-RINGS
1.
All
gaskets, seals and
0-rings
should be re
placed
when
an engine is overhauled.AII ga
skets surfaces,
oil seal lips and
0-rings
must
be cleaned.
2.
Properly
oil all
mating
parts and bearing
during reassembly.
Apply
grease
to
the
oil
seal lips.
YB112004
LOCK WASHERS/PLATES
AND
COTTER
PINS
1.
All
Jock
washers/plates
( ) and
cotter
pins
must
be replaced
when they
are remo
ved.
Lock tab(s) should be bent along the
bolt
or nut flat(s) after the
bolt
or nut has
been properly
tightened.
YB112005
BEARINGS AND OIL SEALS
1. Install
the
bearing(s) and oil seal(s) with
their
manufacturer's marks
or numbers
facing outward.(ln other
words, the stam
ped letters must be
on the
side exposed
to
view.) When
installing oil seal(s), apply
a
light coating
of
light-weight lithium
base
grease to
the seallip(s).
Oil
the
bearings li
berally when installing.
( ) Oil seal
c :;
_
Do
not
use compressed air to spin
the
bearings dry.
This causes damage to
the
bearing surfaces.
( ) Bearing
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300 001
0
1 4
SPECIAL TOOLS
I
~
I
YB112006
CIRCLIPS
1.
All
circlips should be
inspected
carefully
before
reassembly.
Always
replace piston
pin clips after one use. Replace distorted
circlips. When installing a circlip D make
sure
that the sharp edged
corner
is po-
sitioned opposite
to
the thrust
@
it
recei-
ves. See
the sectional view.
@ Shaft
YB113001
SPECI L TOOLS
The prepare special tools are necessary for
complete and
accurate
tune up and assemb-
ly. Using
the correct
special
tool
will help pre-
vent
damage caused
by the
use
of
improper
tools or
improvised
techniques.
FOR TUNE UP
1. Inductive timing light
P/N. YM 33277
This tool is
necessary for
adjusting
ignition
timing.
2. Fuel level gauge
P/N.
YM 01312
This tool
is used to
measure the fuel
level in
the float chamber.
3. Inductive tachometer
P/N. YU 08036
This tool is needed for detecting engine
rpm.
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1 5
SPECI L TOOLS
~ ~ ~ I
FOR ENGINE SERVI E
1.
Universal clutch holder
P/N. YM 91042
This tool
is used
to
hold
the clutch when
loo-
sening or tightening
the clutch
boss
locknut.
2. Universal
rotor holder
P/N. YU 01235
This
tool
is used
when
loosening or
tigh-
tening the flywheel magneto
securing
bolt.
3.
Flywheel
puller
P/N. YM 01189
This tool
is used
for
removing
the flywheel.
4. Piston pin puller
P/N. YU 01304
This tool
is used to remove
the
piston pin.
5. Crankshaft
separating tool
P/N. YU 01135
This tool is used to split the crankcase as
well as remove the crankshaft
from
either
case.
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1 6
SPECIAL TOOLS ~ ~ ~ I
6.
Crankshaft
installing
tool
D
P/N. YU 90050
Adapter
P/N. YM-90063
These tools
are used
to
install
the
cranksha
ft
FOR CHASSIS SERVICE
1.
Front fork
seal
driver
Weight) D
P/N. YM-33963
Adapter
P/N. YM 33281
This
tools
used
when
installing
the fork
seal.
2. Slide hammer
set
P/N. YU 01047
This
tool is used
when
disassembling
the
front
fork.
3.
Ring nut
wrench
P/N. YU 33975
This tool
is used to loosen and
tighten the
steering
ring
nut.
FOR ELECTRICAL COMPONENTS
1 .
Dynamic spark
tester
P/N. YM-34487
This instrument
is necessary for checking
the ignition
system
components.
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1
7
S
PECIAL T O
OLS
'i
2.
P
ocket teste
r
P/N .
YU-03112
This
tester
is invaluable
for
checking
the ele
ctrical syst
em
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~ ~ ~ ~ ~ ~
1 8
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~ ~ ~ ~ ~ ~ ~ ~ ~ G E _ N _ E _ R _ A L _ s _ P _ E _ c i _ R _ ~ _ T _ I O _ N _ s ~ I S P E C ~
SPECIFIC TIONS
GENER L SPECIFIC TIONS
Model
RT100A
Model Code Number: 3UL1
Vehicle Identification Number:
JYA3ULWO*LC0001
01
Engine Starting Number: 3UL-000101
Dimensions:
Overall Length
1,795
mm
70.7 in}
Overall
Width
760 mm (29.9 in}
Overall Height
960 mm (37.8 in}
Seat Height 730 mm 28.7 in}
Wheelbase 1,190
mm 46.9
in}
Minimum
Ground Clearance
200 mm
7.9
in}
Basic Weight:
With Oil and Full Fuel Tank 79 kg (1741b}
Minimum
Turning Radius:
1,810
mm 71.3
in}
Engine:
Engine Type
Air cooled 2-stroke
Induction System
Reed
valve
Cylinder Arrangement
Forward inclined single cylinder
Displacement 97cm
Bore
X
Stroke
52.0
X
45.6
mm 2.05 X 1.80
in}
Compression Ratio 6.7:1
Starting System Kick starter
Lubrication System:
Type
Separate lubrication (Yamaha Autolube}
Engine Oil Type Yamalube 2
or
air cooled 2 stroke engine oil
with
BIA certified for service TC-W
Transmission Oil Type
Yamalube
4 , SAE
10W30 type
SE motor
oil
or
GL gear oil
Oil Capacity:
Engine Oil (Oil Tank}
1.0
L
0.88
Imp qt,
1.06 US
qt}
Transmission Oil:
Periodic Oil Change 0.65 L (0.57 Imp qt, 0.69 US qt}
Total
Amount
0.65 L 0.57 Imp qt,
0.69 US
qt}
Air Filter
Type Wet
type element
2-1
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Model
Fuel:
Type
Fuel Tank Capaci ty
Full Amount
Reserve
Amount
Carburetor:
Type Quantity
Manufacturer
Spark Plug:
Type Quantity
Manufacturer
Plug Gap
Clutch:
Type
Transmission:
Type
Primary Reduction System
Primary Reduction Ratio
Secondary Reduction System
Secondary Reduction Ratio
Operation
Gear Ratio
1st
2nd
3rd
4th
5th
Chassis:
Frame
Type
Caster Angle
Trail
Tire:
Type
Size
Front
Rear
Tire Pressure Cold Tire):
Basic Weight:
With
Oil and Full Fuel Tank
Cold Tire Pressure:
GENERALSPECIFICATIONS
I
PEC IP
RT100A
For USA) Unleaded fuel recommended
For CON) Regular unleaded gasoline
5 0
L 1.10
Imp
gal, 1.32 US gal)
1 5
L 0.33
Imp
gal, 0.39 US gal)
VM22SS/1 pc.
MIKUNI
For USA) 87ES
For CON)
BR7ES
NGK
0 5
- 0.6
mm
0.020 - 0.024 in)
Wet,
multiple
disc
Constant mesh 5-speed
Helical gear
74 19
3.895)
Chain drive
48 14
3.429)
Left
foot
operation
35/11 3.182)
30/15 2.000)
26/19 1.368)
23/23 1.000)
20/25 0.800)
Double cradle
29
103
mm
4.06 in)
With tube
2.50-184PR
3.00-164PR
79
kg
1741b)
FRONT
125 kPa
1.25
kg cm
2
18 psi)
? ?
REAR
125
kPa
1.25 kg cm
2
, 18 psi)
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GENE
RALSPECI
FICATIONS
PEC P7
Model
R
T100A
Bra
ke:
Front Brake Ty
pe
D
rum brake
Fron t Brake
Operation
Right hand op
erat ion
Rear Brake T
ype
Drum brake
Rear Brake Operation Right
oot
operat ion
Suspensi
on:
Front
Suspension Ty
pe
Telesco
pic fork
Re
ar Suspension T
ype
Swin
garm
Shock Absorbe
r:
Front Shoc
kAbsorber
Coil spring/O
i l damper
Rear Shoc k
Absorber Coil sprin
g/Oi l damp er
Wheel
Travel:
Fr
ont Wheel Trav
el
110
mm 4.3
in
Rear Wh eel Tra
vel
84
mm
{3.3 in
Electrical:
Ignit ion
System
CDI Magn
eto
Gener
ator System
Flywhee
l magneto
2-3
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MAIN
TENANCE
SPECIFICAT
IONS I
PE I
I
M INTE N
NCE S PECI
FIC TIONS
NGIN
Cylinder He
ad:
Warpag
e Limit
Cylinder:
Bore
Size
Ta
per Lim it
Model
Out of Round
Limit
Piston:
Piston
Size
D
Mea
suring Point a
Piston Off-Set
Piston-t
o-Cylinder Clear
ance
Ove
rsize 1st
Oversize 2nd
O
versize 3rd
Oversize 4th
Piston R
ing:
Se c
tional Sketch
End
G
ap (Installed)
S
ide Clearance
Top
ing
C]]
s
1
T
2nd Ring
DJs
1
Top Ring
2
nd Ring
Top Ring
2nd Ring
RT100A
0
.03
m
m 0.0012
in)
*
Lines indicate s
traightedge mea
surement.
52.00- 52.02
mm 2.047- 2.
048 in
0.05 mm
0.002 in)
0.
01mm
0.0004 in)
51.94- 52.00 mm
2.045- 2.047
in)
10 mm 0.39 in)
0.5
mm 0.020 in)
0.0
50 - 0.055mm
0.00 20 - 0.00
22
in
)
5
2.25 mm 2.057
in)
52.50 m
m
2
.067 in)
52.75
mm 2.077 in)
53 .00
mm
2.087
in)
K
eystone type
8=1.2 mm 0.
047 in).
T=2.0 mm
0.079 in)
Plain type
8=1 .2
mm 0.047 in)
T=1.6
mm 0.063 in)
0.3 - 0.5
mm
0.01
- 0.02 in)
0.3 - 0.5 mm
0.01 - 0.02 in)
0.03 - 0.0
5
mm
0.001 -
0.002 in)
0.03 -
0.05 mm 0.001
- 0.002 in)
2-4
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Cranksha
ft:
Cran
k Width A
R
unout Limit B
Model
Big End Side C
learance C
Small
End
Free
Play
D
D
Clutch:
Friction Pla
te:
Th
ickness
Quant i ty
Wear L imi t
Clutch Plat
e:
Thickn
ess
Quan
tity
Warpage Lim
it
Clutch S pring
:
F
ree Length
Quant i ty
M in i
m u m Free Lengt
h
Clu
tch Release Me
thod
Transmission
:
Main Axle
Runout Limit
Dr
ive Axle R unou
tLimit
Shifter:
Type
Guid
e Bar Bending
Limit
Kick
S tarter:
Type
MAINT
ENANCESP
ECIFICATIO
NS I
PEC I
? 7
I
RT100A
49.90-
49.95
mm (1.965- 1.967
in)
0.0
3 mm
(0.00
12 in)
0.2 - 0.7 mm
0.008 -
0.028 in)
0.8 - 1.0
mm 0.032
- 0.039 in)
3.0 mm 0.120 in)
5
p
es.
2.7
m
m
(0.1
06 in)
1.2 m
m
0.047
in)
4 pes.
0.05
mm (0.002
in)
31.
5 mm
1.24
in)
5 pes.
30.5 mm
1.20 in)
Inne
r push, cam pu
sh
0
.08 mm (0.
003 in)
0.08 mm 0.00
3 in)
Cam d
rumand guide bar
0.025
mm
0.001
in)
Kick
and Mesh type
2-5
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M
INTEN NC
ESPECIFIC
TIONS
I PEC
I 7 1
Model
RT
100A
Air
Filter:
Oil Grade
Foam-A
ir-Filter oil
or
Ya
malube 2
Carbu
retor:
I.
D. Mark 3
ULOO
M a
in Jet (M.J.)
140
Air
Jet
A.J.)
~ 2 5
Je
t
Needle
-Posit ion
J.
N.) 4L 6-3
Needle J
et N.J.) 0-6
Cutaw
ay (C A)
2.0
Pilot O
ut let
P.O.)
Pilot Je t
P.J.)
17.5
AirScrew
A.S.) 1-1/2
Valve Sea
t Size
V.S
.)
~ 1 5
Starter
Jet
G.S.) 30
Fuel Le
vel F.L.)
-0.5 - +0.5 m
m (-0.02 - +0.02
in)
Float
Height F.H.)
20 - 22
mm
(
0.79 - 0.87 in)
Id
l ing Speed 1,3
00- 1,450 r/min
Reed Valve:
Valve T
hickness 0.2 mm
(0.008in)
Valve
Stopper Heig
ht
6.7 - 7.3 mm 0.26
- 0.29 in)
Va
lve Bending Lim
it 0.3 mm(0.012
in)
Lubrication
System:
Autolub
e Pump
Color Code
Green
Minimu
m
Strok
e 0.20- 0.25 m
m (0.008- 0.010
in)
Maximu
m
S
troke 1.85
-
2.05
mm (0.073- 0.081
in)
Minimum Outpu t
0.50
-
0.62
cm
per
200
strokes
Maximum O utput 4.6
4 - 5.15cm
p
er
200
st rokes
Pul
ley Adju st ing M
ark At idle
2-6
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M INTEN
NCESPEC
IFIC TION
S IPEC
I 1)5/ I
T IG H T N ING T
ORQU
Tightening t
orque
Part to
be t ightened
Bolt Nut
size
Nm
mkg
ftlb
Sparkplug
M14
X 1.25 2
5 2.5
18
Cylinder h
ead
M8 X 1.25
22
2.2
1
6
Auto lube
pump
M 5
X
0.8
4
0.4
2.9
In t
ake man ifold
M6
X
1.0
10 1
.0 7.2
Muffl
er Front)
M6
X
1.0
8
0
.8
5.8
Muffler Rear)
M 8
X
1.25
18
1.8
13
Crankcase
M6
X 1.0
8
0.8
5.8
Crankcase
cover Right)
M6
X 1.0
10
1
.0
7.2
Crankcas
e cover Left)
M6
X 1.0
7
0.7
5.1
Transmis
sion oil drain
bolt
M
12 X
1.5
20
2.0 14
A
utolube
pump
c
over
M6
X 1.0
8
0.8
5.
8
Kic
k crank assemb
ly
M8
X
1
25 16
1.6
11
P
rimary dr ive ge
ar
M12
X 1.0
60
6.0
43
Clutchboss
M12
X 1.0 45
4 5
32
Pressure
plate
M 5
X 0.8
6
0.6 4.3
Stoppe
r plate Bearing
)
M6
X
1.0
10 1
.0
7.2
Sh
if t cam stopper
bolt Neutral)
M14
X
1.5
25
2.5 18
Change pedal
M6 X 1.0 11
1.1
8.0
Drive sproke
t
M16
X 1.0
55 5.5
40
Stato r
M6 X 1.0 8
0.8
5.8
COl
m a
gneto
M
12 X 1.0
50 5.0
36
2 7
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MAINTE
NANCESPE
CIFICATION
S I PEC I
>7
CH
SSIS
Model
RT
100A
Steering Sy
stem:
Bearing
Type
Ball Bea r
ing
Bearing
Size Quantity)
Upp
er
3/16 in 22 pes.)
Lower 1/4 in
19
pes.)
Front Suspens
ion:
Front Fork
Travel
110
mm
4.33 in)
Fork Sp
ring FreeLength
Left side only)
418.5 mm
16.5 in)
Sp
ring Rate
K,)
4.2
N/m
m 0.42 kg/mm
, 23.5lb/ in)
K2)
5.
7
N
/mm 0.57 kg
/mm, 31.91b/
in)
Stroke
K,) 0.0 -
70.0 mm 0.0 - 2.8 i
n)
K2)
7
110
mm 2.8 - 4.3 in
)
Optional S
pring No.
Oil Cap
acity
110
cm
3.87
Imp oz,
3
.72 US oz
)
Oil
Grade
Yam
aha forkoii
10WT or equivalen
t
Rear
Suspens
ion:
Shock Ab
sorber Travel
75 mm
2.95 in)
Spring
Free Length
205.6 m
m 8.09 in)
Fi t
t ing Length
201.
6 mm 7.94 in)
Spring Rate K
,)
11
N
/mm
1.1 kg/mm
,
61.61b/in)
K2)
17.4 N/mm 1.
74 kg/mm, 97.4
lb/ in)
Stroke
K,)
0.0-
50
mm
0.0
-
1.9
7
in)
K2)
50
-
75 mm 1.97 -
2.95 in)
Optional
Spring No.
Swingarm:
Free Play Lim
it Swingarm en
d)
1
.0 mm 0.0
39 in)
M ove sw
ingarm end sid
e to side
Fro nt Whe
el:
T
ype
Sp
orke whee l
Rim Size
18 X
MT1.40
Rim Materia
l Steel
Rim Run
out Limit
Ve
rtical 2.0
mm 0.08 in)
Lateral
2.0
mm 0.08 in)
2-8
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~ ~ ~ ~ ~ ~ ~ - M _ A _ I N _ T _ E N _ A _ N _ c _ E _ s _ P _ ~ _ I F _ I C _ A _ T _ I o _ N _ s _ I S P E C I I
Model RT100A
Rear Wheel:
Type Sporke wheel
Rim Size
16 X MT1.60
Rim Material
Steel
Rim Runout Limit
Vertical
2.0
mm
0.08 in)
Lateral 2.0
mm 0.08
in)
Drive Chain:
Type/Manufacturer
RS420/TSUBAKIMOTO
Number of Links
103
Links
+ oint
Chain Free Play
20
30 mm 0.8- 1.2 in)
Front Drum Brake:
Type
Leading, trailing
Drum Inside Diameter
110 mm
4.33
in)
< 111 mm
4.37
in)>
Shoe Spring Free Length
34.5
mm
1.36 in)
Lining thickness
4
mm
0.16 in)
Rear Drum Brake:
Type Leading, Trailing
Brake Drum Inside Diameter
110 mm 4.33 in)
< 111 mm 4.37 in)>
Shoe Spring Free Length 34.5 mm 1.36 in)
Lining Thickness 4 mm
0.16
in)
Brake Lever and Brake Pedal:
Brake Lever
Free
Play 5 - 8 mm 0.20 -
0.31
in)
Brake Pedal Free Play
20 30
mm 0.8-
1.2
in)
Below top of footrest
Clutch Lever and Throttle Grip:
Clutch Lever
Free
Play
2
3 mm 0.08- 0.12 in)
Thrott le Cable
Free
Play 3 5 mm 0.12- 0.20 in)
At grip flange
2-9
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MAINTENANCESPECIFICATIONS
I
PEC
I f I
TIGHT NING TORQU
Tightening torque
Part
to be
tightened
Bolt Nut
size
Nm
mkg ftlb
Chassis:
Engine mounting;
Front upper
M8
X
1.25 26
2.6
19
Rear upper
M8
X
1.25
26
2.6
19
Rear lower
M10
X
1.25
39
3.9 28
Pivot shaft and nut
M12 X 1.25
43 4.3
31
Rear shock absorber and frame Upper)
M12 X 1.25
39 3.9 28
Rear shock absorber and rear arm Lower)
M10 X 1.25
25 2.5
18
Handle crown and inner tube
M8
X
1.25
26
2.6 19
Handle crown and handlebar
M8
X 1.25
20
2.0 14
Under bracket and inner tube
M10
X
1.25
39
3.9 28
Under bracket and steering lock M5
X
0.8
6 0.6
4.3
Steering ring nut
M25 X 1.25
6 0.6
4.3
Refer
to
NOTE
Handle crown and steering shaft
M14 X 1.25
65
6.5
47
Front wheel axle and nut
M12 X 1.25 43 4.3
31
Brake cam lever and camshaft
M6
X 1.0
9
0.9
6.5
Rear wheel sprocket and wheel hub
M8
X 1.25
20 2.0
14
Tension bar and plate
M8
X 1.25
18
1.8
13
Tension bar and rear arm M8
X 1.25
18 1.8
13
Rear wheel axle and nut M10 X 1.25
39
3.9
28
Sproket shaft and rear arm M18 X 1.0 85 8.5
61
Footrest and frame
M8
X 1.25
18 1.8
13
NOTE
1.
First, tighten the ring nut approximately 36 Nm 3.6 mkg, 25 ftlb) by using the torque wrench,
then loosen the ring nut one turn.
2. Retighten the ring nut to specification.
2-10
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MAINTENANCESPECIFICATIONS
I
PEC
I >7
ELECTRIC L
Model
RT100A
Ignition System:
Ignition
Timing
(B.T.D.C.)
27
at
2,000
r/min
Advancer
Type
Electrical type
30
< J
/
c i
.... :
~
&
g 20
E
;::;
c:
0
;::;
c
..2
10
0
1 2 3
4
5 6
7 8
Engine speed X1,000 r/min)
C.D.I.:
Magneto Model/Manufacturer
F3T1 0471 /MITSUBISHI
C.D.I. Unit Model/Manufacturer
F008T MITSUBISHI
Pickup Coil Resistance Color)
9 - 11Q at 2oc 68.F)
White/Red-Black)
Source Coil Resistance Color)
270 - 330Q at
2oc
68.F)
Brown-Black)
Ignition Coil:
Model/Manufacturer
F6T411 /MITSUBISHI
Minimum
Spark Gap
6
mm
0.24 in)
Primary Coil Resistance
0.9 -
1.1
Q at
2oc
68.F)
Secondary Coil Resistance
4.7 - 7.1
kQ
at 20c 68.F)
Spark Plug Cap:
Type
Resin
Type
Plug Cap Resistance
4 - 6kQ at
2oc
68.F)
2-11
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GENERAL
TORQUE
SPECIFICATIONS/DEFINITION
OF
UNITS
I PEC I I
GENERAL TORQUE SPECIFICATIONS
This chart specifies torque for standard fas
teners with standard I.S.O. pitch threads. Torque
specifications for special components or assem
blies are included in the applicable sections
of
this book. To avoid warpage, tighten multi-fas
tener assemblies in a crisscross fashion, in pro
gressive stages, until full torque is reached. Un
less otherwise specified, torque specifications
call for clean, dry threads. Components should
be at room temperature.
A: Distance across flats
8: Outside thread diameter
DEFINITION
OF
UNITS
Unit
Read
A
(Nut)
10mm
12mm
14mm
17mm
19mm
22mm
Definition
mm millimeter
10-
3
meter
em centimeter
10
2
meter
kg kilogram 10
3
gram
N
Newton
1 kg X
m sec
2
Nm
Newton meter
Xm
mkg
Meter
kilogram
m X
kg
Pa Pascal N m
2
N mm
Newton per millimeter
N mm
L Liter
cm
3
Cubic centimeter
r min
Revolution per
minute
2 12
B
General torque
specifications
(Bolt)
Nm
mkg
ftlb
6mm
6 0.6 4.3
8mm 15 1.5
11
10mm
30 3.0 22
12mm
55 5.5
40
14mm
85 8.5 61
16mm
130
13.0
94
Measure
Length
Length
Weight
Force
Torque
Torque
Pressure
Spring rate
Volume or capacity
Engine speed
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LUBRICATION POINTS AND LUBRICANT TYPE I PEC I p I
LUBRIC TION POINTS
ND
LUBRIC NT
TYPE
ENGINE
Lubrication Points Part name) Lubricant Type
Oil seal lip
0 ring
: . 1 ~
Small end/Big end bearing
Gl
Bearing
Gl
Piston ring
Gl
Piston
Gl
Cylinder inner surface
Gl
Piston pin
Gl
Kick axle
Gl
Primary driven/drive gear
Gl
Push rod
Push lever
Gl
Guide bar Shift fork)
Gl
Shift shaft
Gl
Shif t cam
Gl
CH SSIS
Lubrication Points Part name) Lubricant Type
Steering Upper/Lower balls
Front/Rear wheel oil seal lip
: . 1 ~
Brake cam shaft
Brake pedal pivot
Handlebar Right) end
Sidestand pivot
Gl
Clutch lever pivot/cable end
Gl
Brake lever pivot/cable end
Gl
Pivot shaft
2 13
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C BLE R
OUTIN
CD
Handlebar sw
itch
Swi
tch lead band
Throttle grip
uel tank breather
hose
CA
BLE ROUTIN
G I
PEC I 7
[
]
Pass
the brake cable
outside o the c l
utch cable.
2 14
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C BLE RO U
T I NG
D
Cable guide
Throt t le
cable
Clamp
DI m ag
neto lead
@
O
il hose
Clamp
J)
Engine breather
hose
@
Clutch cable holder
Clutch cabl
e
Clamp
2 15
CABLE
ROUT ING
I PE
I
7
lAJ
C
lamp the DI uni
t lead
[
B
Clamp the D
I m agneto lead a
nd engine breath
er
ho
se
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C BLE ROUTING
D
Clamp
Oil tank breather hose
Carburetor overflow air bent hose
Oil delivery hose
CDI unit lead
@Clamp
j) Spark plug lead
Engine stop switch lead
Ignition coil lead
CABLE ROUTING
I PEC I f I
[A] Clamp the engine stop switch lead
[6] Do not clamp the oil delivery hose
[ J
To
CDI
unit
~
2 16
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INTRODUCTION/PERIODIC MAINTENANCE :gj I
I
LUBRICATION INTERVALS
_ . _
PERIODIC INSPECTION ND ADJUSTMENT
INTRODUCTION
This chapter includes all information necessary
to
perform recommended inspections and adjust
ments. These preventive maintenance procedures, if followed, will ensure more reliable vehicle oper
ation and a longer service life. The need for costly overhaul work will be greatly reduced. This informa
tion applies to vehicles already in service as well as new vehicles that are being prepared for sale. All
service technicians should be familiar with this entire chapter.
PERIODIC MAINTENANCE LUBRICATION INTERVALS
ITEM REMARKS
Spark plug
Check condition. Clean or replace if necessary.
Air filter
Clean. Replace if necessary.
Carburetor*
Check idle speed/s tarter operation.
Adjust if necessary.
Fuel line
Check fuel hose
for
cracks or damage.
Replace if necessary.
Check oil level / oil leakage. Correct if necessary.
Transmission
oil
Replace every 4 months.
(Warm engine before draining.)
Autolube pump Check operation. Correct
if
necessary. Air bleeding.
Brakes* Check operation. Adjust if necessary.
Clutch Check operation. Adjust if necessary.
Check rear arm assembly for looseness.
Rear arm
pivot
Correct
if
necessary.
Moderately repack every 24 months.
Wheels*
Check balance/damage/runout/spoke tighteness.
Repair if necessary.
Wheel bearings*
Check bearings assembly for looseness/damage.
Replace if damaged.
Steering bearing* Check bearings assembly
for
looseness. Correct
if
necessary. Moderately repack every 4 months.**
Front forks Check operation/oil leakage. Repair if necessary.
Rear shock absorber* Check operat ion/oi l leakage. Repair if necessary.
Drive chain
Check chain slack/alignment.
Adjust
necessary.
Clean and lube.
Fittings/Fasteners*
Check all chassis fittings and fasteners.
Correct
if necessary.
Sidestand* Check operation. Repair if necessary.
It is recommended
that
these items be serviced by a Yamaha dealer.
Medium weight wheel bearing grease.
3 1
BREAK-IN
EVERY
1 month 6 months
12 months
REPLACE
Every Ride
(More often in
wet
or dusty areas)
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-
ji
ANDSJP
j uj
IDLING S
PEED
A
DJUSTMEN
T
. . lr:i
.
3 2
YB1AE 4
ENGINE
ID LING SPE
ED
ADJUSTM
ENT
1. Start the en
gine and le
t i t warm
up for se -
vera
l minutes.
2
. Attach:
I
nductive tachome
ter
(to
th
e spar
k
plug le
ad .
Inductive
tachometer:
Y
U-08036
3
. C
heck:
Eng
ine id l ing spee d
Out of
specifica
tion
-
Adjus
t.
Engine
idlin
g
speed
1,
300 1
,4 50 r/min
4. Adjust:
Engine idl ing
s peed
Adj
ustment
steps:
T
urn
in t
he pilot air s
crew
D
until it is l igh-
t ly seated.
Turn
out
the
pi l
ot
air
screw for the spec i -
fied num
ber
o
f turns
.
Pilo
t air
scr
ew:
1 and
1/2 turns out
Tur
n
the thro
ttle
stop scre
w
in
or out
until s
pecified
id
l ing speed
is obtained.
Turni
ng in
Idling
speed
be-
comes hi
gher.
T
urning ou t
Id l
ing
sp
eed be-
com
es
lowe
r.
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_
____
____
____
___
___
I
1
ANDS
JPI al
HROTT
LEC BLE
DJUSTMEN
T _ ~
_
3 3
5 Adjust:
T
hrottle ca
ble free play
Refe r
to
T HRO T T
LE CABLE FRE
E PLAY
ADJU
STMENT section.
Free play:
YB1A
E 008
3
5 mm 0
.12
0
.20 in}
at
throttle
grip
flange
THROTTLE
CABLE
ADJUSTMEN
T
NOTE
E
ngine idling sp
eed shou ld b
e adjusted p r
o-
per ly
before adjus t
ing the
thro
tt le
cable fr
ee
play
1. Check:
Thr
ottle cabl
e free play @
Out
of
specific
ation - Adjus
t.
Fr
ee play:
3 _ 5
mm 0.12 _ 0.20
in}
at throttle
grip
flange
2 Adju
st:
Thrott
le cable fr
ee play
********************
************
*****
Adjus
tment steps:
Loosen the
locknut
D
.
Tu
rn the
adjuster in or out
until the
specif
ied
free
play is obta i
ned
Turning in
Turn
ing
out
Free pla
y
is
increased
.
Free
play
is
decreased
Tighten
th
e locknu
t.
_
WARNING
After
adjusti
ng
turn
the h
and lebar to
right
and
le
ft and
m
ake sure
th
at t
he eng
ine
id
ling does
not
runfa
ster.
************
************
************
*
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3 4
Y81AC002
UTOLU
BEPUMPC B
LE DJUSTM
ENT
NOTE
Engine id
l ing speed an
d throt
tle
ca b
le
free
play should be
adjusted
proper l
y before
ad
ju -
sting
the
auto
lube pum
p
cabl
e
1.
Re
move:
Auto
lube
pump
co
ver
D
2 Close
the throttle
complete
ly
3 Check
:
Align
ment mark @
No
t l i g n e d ~ Adju
st Autolube
pump cable
4 Adjust:
Autolube pump cable
Adjustme
nt steps:
L
oosen th
e locknu
t
D .
Turn
the
adjuster
in
or out until
the
alig-
nment mark is al igned
with
the
pin
Tighten the
locknut
5
1nstal l :
A
utolube pump c
over
YB 1A C004
UTOLUBE
PUMPSTROK
E DJUSTMEN
T
1
R
emove:
Autolu
be
pump
cov
er
D
2
Start
the
engine and
le tit w
arm up fo r se-
veral m
inutes
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3 5
3.
W
hile r
unn ing the en
gine at
idle , observe
th
e pump adjusting
p la t
e
carefu
lly.
Stop
the engine the
momentthat t
he ad jus t i
ng
plate D mo
ves out to
it s
l
imit.
4. M e
asure :
Gap
Out
of c i f i
c a t i o n ~ A d j u s t
Measure th
e gap with
the thickness ga
uge
betwee
n
th
e ra ised os
s
on
the
pump
ad
just ing pu l le y
and
t
he ad jus t
ing p la te D.
Minimum pumpstro
ke:
0
.20-0.25 m
m
0.008-0.010
in
NOT
E
W
hen inserting
the thick
ness gauge
bet-
ween
t
he
adju
sting
p la te and
the
ad jus t in g
pu
lley, be careful t
hat neither the
p la te nor
th
e
p
ul ley is moved.
In othe
r
w
ords do not
force
th
e thic
kness gauge
in to
the
gap.
5. A
djust:
Autol
ube
pu
mp minimum
stroke
*******
************
************
******
A
djustment st
eps:
Remove
th e
locknut
D
spring
washer
and adjusting
p la te
.
Adj
us t
the pum
p
st roke by adding
or
remo-
ving
a
sh
im
@
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AUTOLUBE
PUMP
AIR BLEEDING
3-6
Adding shim
Pump stroke is increa-
sed
Removing shim
Pump stroke is dec-
reased
Install
the
adjusting plate, spring washer
and
locknut.
Locknut:
7Nm 0.7m kg 5.1f t lb)
Recheck the minimum
pump stroke. If
out
of specification, perform the above steps
again.
6.1nstall:
Autolube pump
cover
YB1AC005
AUTOLUBE PUMP AIR BLEEDING
glliiiiJ
The Autolube pump
and
delivery
lines
must
be bled
on
the
following occasions:
Setting up
a new
machine out of the crate.
Whenever the oil
tank has run
dry.
Whenever any
portion
of the engine
oil
system is disconnected.
1.1nspect:
Engine oil level
Oil level
low-+Add
oil
to proper
level.
Refer
to the
W NGIN OIL LEVEL INSPEC
TIOW section.
2. Remove:
Autolube
pump
cover
D
3. Air bleed:
Pump case and/or oil
hose
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3-7
Air
bleeding steps:
Place a .rag
under the Autolube
pump
to
catch
oil.
Remove
the
bleed
screw G .
Keep
the
oil running out
until
air bubbles di
sappear.
When
air bubbles are expelled
completely
tighten the
bleed
screw.
NOTE
Check
the
bleed screw gasket.
If
damaged
replace with a new one.
4.
Air bleed:
Pump distributor and/or delivery
hose
Air bleeding
steps:
Start the
engine.
Pull the pump cable G all the way out to
set
the pump stroke to a maximum.
NOTE
It
is difficult
to
bleed
the distributor
comple
tely with the pump stroke at
a minimum and
therefore the
pump
stroke
should be
set
to a
maximum.
Keep
the
engine running at about 2 000 r/
min for two minutes or
so
then both
dis
tributor and
delivery
hose can be complete-
ly bled.
5.1nstall:
Autolube pump cover
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N
DSJP I ~
PARKPLU
G INSPECT
ION
11 ':/
3 8
YB1AA009
SPARK
PLUG
INSPE CTION
1.
Remove
Spark plug
2
. Inspect:
Spark plug ty
pe
l n c o r r e c
e p l a c e
Standar
d
sp
ark
p lu
g:
For
USA . . B7ES/N
GK
For
CDN . .. BR7ES
/NGK
3.1
nspect:
Elec
trode CD
W
e a r / D a m a g e ~
R e p l a c e .
Insu
lator
Abnor
mal r ~ R e p l a c e
Nor m a l colo
r is a medium-
to-light
tan
co
lor.
4
.
C
lean the spar
k plug wi
th
a
spark plug
c le
aner or wir
e
b
rush.
5.
M e a s
ure :
Plug
g p
Use a Wir
e Gauge or Fee
ler Gauge.
Out
of
specification Re
-gap.
Spark p lu g gap:
0 . 5 ~ 0 . 6
mm
0 . 0 2 0
~ 0 . 0 2 4 in}
6 .
Tighten:
Spark plug
Spark plug:
25
N
m 2.5
m
kg, 18 f t
lb}
NOT
E
Bef
ore
in
stall in g a
spark plug, cle
an the
g
asket
s
urface and plug
surface.
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3 9
YB1AA012
IGNITION
TIMING
CHECK
NOTE
Engine idling speed and
throttle
cable
free
play should be adjusted properly
before
chec
king the ignition
timing.
1. Remove:
Crankcase
cover
left) D
2. Attach:
Timing light and inductive tachometer
Timing
light:
YM-33277
Inductive tachometer:
YU-08036
3.
Check:
Ignition
timing
Checking steps:
Warm
up
the
engine and keep
it
at
the spe
cified speed.
I
ngine speed:
. 2,000 r/min.
Visually
check
the stationary
pointer
D
to
verify
i t is within
the
required firing
range indicated on
the
timing plate.
Incorrect
firing
range-+Check
timing
plate
and/or pickup assembly.
4.1nstall:
Crankcase cover
{left)
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ENGINE OIL LEVEL INSPECTION/TRANSMISSION
OIL
LEVEL
IINSP I
I
INSPECTION DJ
...:......::=;.... j..._
YB1AC007
ENGINE OIL LEVEL INSPECTION
NOTE
Position the
machine
straight up when
inspe-
cting
the
oil level
1 Place
the
machine on a level
surface.
NOTE
Piace a suitable
stand
under
the
engine
2
Check:
Oil level
Oillevellow-+Add
sufficient
oil
D
Oil level window
Recommended oil:
Yamalube 2 or
air cooled
2
stroke
engine
oil
with
BIA cer
ti f ied for service TC-W
Oil
tank
capacity:
1 0
L(0.88 Imp
qt,
1.06
US qt)
Always use the same type of engine
oil;
mixing oils
may
result in a harmful
chemical
reaction and lead to
poor
performance.
YB1AC039
TRANSMISSION OIL LEVEL INSPECTION
1. Place the machine on a level place
N O T E ~ -
Piace a suitable stand under
the
engine
3-10
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2.
Inspect:
Oil level
Oil level should be
between maximum D
and minimum marks.
Oil level is
low
-
Add
oil to proper level.
NOTE
Do
not screw
the dipstick
Insert the
dip
stick
lightly
when
inspecting
the
oil level.
Recommended oil:
Yamalube 4
or
SAE 10W30
type SE motor
oil
NOTE
Recommended oil classification; API Service
se, sF type or
equivalent (e.g.
sF-se,
SF-SE-cc,
SF-SE-SD
etc .
Do
not add any
chemical additives. Trans
mission oil
also
lubricates the clutch and
additives
could cause clutch
slippage.
Do not allow foreign material to enter
the
crankcase.
A WARNING
Never attempt to remove the dipstick
just
after high
speed
operation. The heated oil
could spout
out,
causing
danger. Wait until
the oil cools down.
3.
Start
the engine and
let
i t
warm up
for se
veral minutes.
4.
Stop the
engine and
inspect the
oil level
once again.
NOTE
Wait a few minutes until settles before inspe
cting the
oil level.
3-11
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TRANSMISSION OIL REPLACEMENT/
~ ~
I
CLUTCH
ADJUSTMENT
_ . _
YB1AC042
TRANSMISSION OIL REPLACEMENT
1
Start
the
engine and
Jet
i t
warm up for
se
veral minutes.
2.
Stop the
engine and place an oil pan under
the engine.
3.
Remove:
Oil
filler
plug
Drain plug D
Drain the transmission case of its oil.
4.1nstall:
Drain plug
'
Drain
plug:
~ 20 Nm 2.0 m
kg,
14ft lb)
NOTE
Check the gasket
(drain plug).
If
damaged, re
place i t with a
new
one.
5 Fill:
Transmission
case
Oil
quantity periodic oil
change):
0.65
L
0.57
lmpqt,
0.69
USqt)
Refer to the
TRANSMISSION OIL LEVEL
INSPECTION
section.
YB1AF002
CLUTCH ADJUSTMENT
1 Check:
Clutch
cable free play
Out of specification-+ Adjust.
3-12
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AIR FILTER CLEANING
Free play:
INSP
ADJ
2 3 mm 0.08 0.12
in)
at clutch lever pivot
2 Adjust:
Clutch cable free play
Adjustment steps:
Loosen the locknut s) G .
Turn
the adjuster s)
in or
out
until the
specified free play is
obtained.
Turning
in
Turning
out
Free play is increased.
Free
play is decreased.
Tighten the locknut s).
YB1AB003
AIR FILTER CLEANING
1 Remove:
Seat
G
Side cover
left)
2 Remove:
Air filter case cover G
3 13
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___________________
i
1
ANDSJPJ nJ
IR FILTER CLEANING
_ _
350 000
3. Remove:
Air
filter element D
Element guide
Never operate the
engine with the air
f i lter
element removed. This
will
allow
unfiltered
air to enter causing rapid
wear
and possible
engine damage.
Additionally operation
wi-
thout
the
filter element will affect carbure-
tor tuning
with
subsequent poor performan-
ce
and possible engine
overheating.
4.1nspect:
Air filter
element
Damage ~ Replace.
5
Clean:
Air filter
element
Cleaning
steps:
Wash
the
element gently but thoroughly
in solvent
D
A
WARNING
Use parts cleaning solvent only. Never use
gasoline
or low flash point
solvents which
may
lead
to
a
fire or explosion.
Squeeze the excess
solvent out of the
ele-
ment
and let
dry.
Do
not
twist
or wring
out
the foam
element.
This could damage the foam material.
Apply the
engine oil .
Squeeze out
the
excess oil.
NOTE
The element
should be wet
but not
dripping.
3 14
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FRONT BRAKE ADJUSTMENT
2.
Inspect:
Muffler s)
D
Cracks/Damage-+Replace.
Gasket(s)
Exhaust gas leaks-+Replace.
3.1nstall:
Side cover (right)
Seat
YB1A3002
CHASSIS
FRONT BRAKE ADJUSTMENT
1. Check:
Brake lever free play
Out of
specification-+Adjust.
Free play:
2.
Adjust:
5 8 mm 0.2 0.3 in)
at
brake lever pivot
Brake lever free
play
Adjustment
steps:
Loosen the locknut
D
.
Turn the
adjust er(s)
in
or out until the
specified free
play is obtained.
~ ~ t t ~ i ~ t
Make sure that the brake does not
drag
after adjusting it.
Tighten the locknut.
3-16
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YB1A3006
REAR BRAKE
ADJUSTMENT
1.
Check:
Brake pedal
free
play
Out of specification- Adjust.
~
Free play:
20 30
mm
0.8
1 2
in)
3-17
2. Adjust:
Brake pedal free play
*************************************
Adjustment
steps:
Turn the
adjuster s) D in
or out until
the
specified free
play is obtained.
Turning
in
Free play
is
decreased.
Turning
Free play
is increased.
out
Make sure
that the
brake
does not drag
after
adjusting
it.
*************************************
YB1A4022
DRIVE CHAIN
SLACK
ADJUSTMENT
NOTE
Before
checking and/
or
adjusting, rotate
the
rear
wheel
several
revolutions
and
check
slack
at
several
points to find the tightest
point.
Check and/or adjust
the
chain slack
with the
rear
wheel
in this wtightestw
position.
Too
little
of
chain slack
will
overload
the
engine and
other
vital parts;
keep
the
slack
within the
specified
limits.
A WARNING
Securely support the machine so there is no
danger of i t falling
over.
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I
I N
DSJP ~
I
RIVE CHA IN
SLACK A
DJUSTMEN
T
1. Place the
m achine o
n a level pla
ce, and
hold i t in
an u
pright position.
NO
TE
Both
wheels shou ld be on
the ground
wi
thout the rider on
it.
2 Che
ck:
Drive chain s la
ck
Out of
specification
-+Adjust.
Drive chain slack
:
20 30
mm
0.8
1.2 in }
at
both wh
eels on ground
witho
ut rider
3 .
Remove
Cotterp in
( )
4
.
L
oosen:
Ax
le nut
Sprocket shaft n
ut
5 Ad just:
D
rive
cha
in s lack
****
************
************
*********
Adjustme
nt steps:
Loo
sen the locknut
s) @
Turn
the
ad juster s
) in or
out until the
specified s la ck is ob
ta ined.
Turning in
S lack
is decreased.
Turning
out
Slack
is increased.
NO
TE
T
urn
each
adjuster
exactly the sam e a
mount
to
maintain
correct axle al ignm
ent. There
are
m
arks
o
n
each
side o
f swingarm and on
each c
hain pu ller; use
them
t
o
check fo r
prope
r
al ignm
ent. )
3-18
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I NDSJP ~ I
RIVE
CH IN LUBRIC TION
Tighten
the sprocket
shaft
nut and axle
nut to
specification, while
pushing up or
down on the chain
to
zero slack.
Sprocket shaft
nut:
85Nm 8.5 m kg, 6 f t lb)
Axle
nut:
39 Nm
3.9
m kg, 28f t lb)
Tighten
the locknut s).
6. Install:
Cotter pin D
G,U1 : J(lf4;
Do
not
loosen
the
axle nut after torque
tigh-
tening.
If the
axle
nut groove is not
aligned
with
the cotter
pin
hole,
align
groove
with
the
hole
by tightening
up on
the axle nut.
A WARNING
Always
use a new
cotter
pin.
7. Adjust:
Rear brake
Refer
to
the
WRE R
BRAKE ADJUSTMENT
section.
YB1A4026
DRIVE CHAIN LUBRICATION
The chain consists
of
many parts which
work against each other. If the chain is not
maintained
properly,
it will
wear
out rapidly,
therefore,
form the
habit
of
periodically ser
vicing
the chain.
This service
is especially ne
cessary when riding in dusty conditions.
1. Use any brands
of
spray type chain lubri
cant. First, remove
all
dirt
and mud
from
the
chain
with
a brush or cloth, then spray
a lubricant between both rows
of
side
plates and on all
center
rollers.
2.
To
clean the chain, remove the chain from
the machine, dip it in solvent, and clean
out
as much
dirt
as possible. Take the
chain out
of
the solvent and
dry it.
lmme-
3-19
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1
1
ANDSJPI ul
TEERING HEAD
ADJUSTMENT
_ .
l l : i '
_
diately lubricate the
chain to
prevent rust.
Recommended lubricant:
YB1A1000
Yamaha chain and
cable
lube
or SAE 10W30
motor
oil
STEERING HEAD ADJUSTMENT
AWARNING
Securely
support the
machine
so
there is no
danger of it
falling over.
1 Elevate the front wheel
by
placing a suitab
le
stand
under
the
engine.
2. Check:
Steering assembly bearings
Grasp
the
bottom of
the
forks and
gently
rock the
fork assembly
back
and forth.
Looseness-+Adjust steering head.
3.
Remove:
Front wheel
Refer to
the
FRONT WHEEL
section
in
the
CHAPTER
6.
Seat
Fuel tank
4. Adjust:
Steering head
Adjustment
steps:
3-20
Loosen
the bolt
(handle
crown .
Tighten the
ring
nut
using
the
ring
nut
wrench.
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NOTE
Set the torque wrench
D to
the
ring
nut
wrench
so that they form
a
right
angle.
~
I
ing
nut
wrench:
YU-33975
Ring
nut
{initial tightening):
36
Nm 3.6
m
kg, 25f t
lb)
Loosen
the
ring
nut one turn.
Retighten
the
ring nut using
the
Ring nut
wrench.
WARNING
Avoid
over-tightening.
Ring nut final
tightening):
6 Nm 0.6 m
kg,
4.3 f t
lb)
NOTE -
Recheck
the
steering head
by turning the
steering
from
lock to lock,
after
adjusting
steering head.
If
steering is binded, loosen
the
ring nut
but
not
to
the extent of free play in bearing.
If steering is loosened, repeat
the
adjust
ment steps.
Tighten the bolt
handle
crown).
Bolt handle crown):
65Nm 6.5m
kg 4 7 f t
lb)
5.1nstall:
Fuel tank
Seat
Front wheel
3 21
Refer to
the WFRONT WHEEL section
in
the
CHAPTER 6.
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TIRE INSPECTION
YB1A3014
TIRE INSPECTION
1
Measure:
Tire pressure
Out of specification-+Adjust.
A WARNING
Tire inflation pressure should
be
checked
and adjusted when the temperature of the
tire
equals
the ambient air temperature.
Cold
tire
pressure
Front
Rear
125kPa
125kPa
Off road
riding
1.25kg/oi
1.25kg/cnf
18psi)
2.1nspect:
Tire surfaces
Wear/Damage-+Replace.
Minimum tire tread depth:
front and rear)
4 5 mm
{0 18
in)
D Tread
depth
Sidewall
Wear indicator
A
WARNING
18psi)
It
is
dangerous to ride with a
wornout
tire.
3-22
When
a
t ire tread begins
to
show lines,
replace the tire immediately.
Patching
a
punctured tube is not recom
mended. If it is absolutely necessary to do
so, use great care and
replace
the tube
as
soon as possible with a good
quality
repla
cement.
Do not attempt
to
use tubeless
tires
on a
wheel
designed for
tube
type tires
only.
Tire
failure
and personal injury may
result
from sudden deflation.
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I NDSJP
~ I
IRE INSPECTION _
341 009
3 23
Wheel
Tire
Tube type
Tube
type only
Tubeless Tube type or tubeless
Be
sure
to
install
the correct
tube when
using tube
type
tires.
After
extensive tests, the tires mentioned
below
have
been approved by Yamaha
motor Co.,
Ltd.
for this model. No
guaran
tee
for
handling
characteristics
can
be
given if tire combinations other
than
what
is approved are used on this
machine.
The
front and rear tires
should be of
the
same
manufacture
and design.
Manufacture
Size
Type
Front):
2.50-184PR
KNOBBY
CHENG SIGN
Rear):
3.00-164PR
KNOBBY
CHENG SIGN
WARNING
After
mounting
a tire, ride
conservatively
to
allow
proper
t ire to
rim
seating. Failure
to
do so may
cause an
accident
resulting
in
machine
damage
and
possible
operator
injury.
After a tire repair or replacement, be sure
to torque tighten
the
valve stem locknut
D
to specification.
Valve stem locknut:
1.5 Nm
0.15
m kg, 1.1 t lb}
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WHEEL INSPECTION/SPOKES INSPECTION AND I : g ~ I
I
TIGHTENING/FRONT FORK INSPECTION _ . Ei ' _
YB1A3016
WHEEL INSPECTION
1.1nspect:
Wheels
Damage/Bends-+Replace.
NOTE
Aiways balance the
wheel when
a
tire or
wheel has been changed or replaced.
at
WARNING
Never
attempt
even
small
repairs
to
the
wheel.
YB1A3017
SPOKES INSPECTION
AND
TIGHTENING
1.1nspect:
Spokes
D
Bend/Damage-+Replace.
Loose spoke- Retighten.
2.
Tighten:
Spokes
Spoke wrench
NOTE
e sure to retighten these spokes before
and
after
Break-in.
YB1A1001
FRONT FORK INSPECTION
at WARNING
Securely
support
the machine
so
there is no
danger of
i t
falling over.
1. Place the machine on a level place.
3-24
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I
I NDSJP ~
I
E
AR SHOCK
ABSORBER
AD
JUSTMENT
2 Ch
eck:
ln
nertube
S c r a t c h / D a
m a g e ~ R e p l a c e
Oil se
a l
E
xcessive
i l l e a k a g e ~ R e p
l a c e
3
old
th e machine
on
uprig
ht
p
osition and
apply
the
front bra
ke
4 Check
:
Operation
Pump
th e
front
fork up and
dow
n for
s
e-
veral times
Un
smooth p e r a t i
o n ~ R e p a
Refer to
t
he
W RON
T ORKW section
in the
CHA
PTER 6
YB 1A 2
001
R E A R
SHOCK A B S O
R B E RADJUST
MENT
AWARNING
Alway
s
a
djust each rear
shock absorber
preload to
the
same
settin
g
Uneven adj
us-
tm ent
ca
n
ca
use
poor
handlin
g and
lo
ss of
stability
Securely
supp
ort the
machine
so
there is
no
da
nger
o
f
it falling
over
1
Adjust:
Spr
ing
p
re load
Turn the
adjuste
r D to
direction
or
@
Turn
ing
Spring preload
is
decreased
T
urning@
Spr
ing pre
load
is
in
creased
Adjuster po
sition:
Standard 2
Minimum 1
Maximum 5
Never atte
mpt
to
turn th
e
ad
juster bey
ond
the
maximum
or minimum s
etting
3 25
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CABLE
INSPECTIO
N AND
LU B
RICAT ION/L
EVER
AND PEDAL
NSP
I I
LUB
RICATION/S
IDE ST
AND LUBRICAT
ION DJ
~ . . . ; . ; ; ; ; ; ; ; . . . ; : ; . .
. . . r . . _ _ .
Y81A3018
C A B L EINSPE
CTION
AN
D L
UBRIC ATION
A WARNING
D a m a
ged cable sheath may
caus
e
corro
sion
and
interfere
with
the cable movemen
t. An
u
nsafe condi
tion may
resu
lt so
replace such
cable
as
soon
as possib le.
1 .1ns
pect :
Cable
sheath
Damage-
Replace.
2 Check:
Cable
ope
ration
Unsmooth
op
eration- Lubr
icate.
R eco m m e n
ded
lubricant:
Y amaha chain
and cable
lube
or
S A E
1
0W30 motor
oil
NOTE
Hold cable
end high and a
pp ly several drops
of
lub
ricant
to
cable.
YB
1A3019
L
EVER
AND
PE
DAL LUBRICA
TION
Lubricate the
l v r and peda
l
at their p
ivo
ting
points
.
Y B 1A 5000
R e c o m m
ended
lubric
ant:
Y a m a h
a
chain
and c
able lube
or
S
AE
10W30 moto
r
o il
S IDEST AND
LU BRICATIO
N
Lubricat
e
t
he s
idestand at pivoting
po in ts .
3 26
Recom
m e n ded
lubric
ant:
Y a m a h
a
chain
and c
able lube
or
SAE10W3
0 motor oil
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4 1
ENGINEREMOVAL
I
NG
I I
YB141000
ENGINE OVERHAUL
ENGINE
REMOVAL
NOTE
It
is not necessary to remove the engine in
order to remove
the following components:
Cylinder
head
Cylinder
Piston
and
piston
ring
Primary
drive
gear
Kick
axle
Shift
shaft
CDI magneto
Autolube pump
YB141001
TRANSMISSION OIL
1 Drain:
Transmission
oil
Refer to cHAPTER 3-TRANSMISSION OIL
REPLACEMENT l
Y8141002
SEAT AND SIDE COVER
1
Remove:
Seat
Side covers
left
and right)
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ENGINE REMOV L
NG
I
I
4 2
YB141003
FUEL T NK
1 Turn the fuel cock
to
oFFn position and
disconnect the
fuel
hose D
2 Remove:
Fuel tank
YB141004
MUFFLER
1 Remove:
Nuts
D
2 Remove:
Muffler
YB141005
C RBURETOR
1 Remove:
Carburetor assembly
Refer
to the
cHAPTER 5 CARBURETOR
section
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ENGINE REMOV L
ENGI
1
YB141006
UTOLUBE PUMP C BLE ND HOSE
1.
Remove:
Autolube pump cover
D
2.
Disconnect:
Autolube pump
cable D
Oil hose
Oil
delivery
hose
N O T E
Piug
the
oil hose end with a suitable
screw
- ~ ~ ; : r ~ w j ; 1 vs141 7
LE DS
4-3
1.
Disconnect:
Spark plug lead
D
2.
Disconnect:
COl
magneto
leads
YB141008
CLUTCH C BLE
1.
Disconnect:
Clutch
cable handlebar side)
Clutch
cable engine side) D
YB141009
DRIVE CH IN
1. Remove:
Change pedal D
Crankcase cover left)
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2. Remove:
Cotter pin
D
3
Loosen:
Sprocket
shaft nut
Rear
wheel
axle nut
Lock
nut @
Adjuster
4
Straighten:
Lock washer
D
5 Remove:
Nut
Lock washer D
Drive sprocket
Drive
chain @
YB141010
ENGINE REMOVAL
1. Removal:
Bolts
2. Remove:
Engine assembly from right side
YB142001
ENGINE DISASSEMBLY
CYLINDER HEAD CYLINDER AND PISTON
NO T E
With the engine mounted, the cylinder head,
cylinder and piston can be maintained by re
moving
the following
parts.
Fuel
tank
Muffler
4-4
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EN
GINE DISAS
SEM BLY
I
NG I
~
1. Remove:
Spark p
lug D
Cyl
inder he
ad
2.
Re
move:
Gas
ket cy
linder head) D
Cylin
der
Gaske
t cyl inder )
Intake man
ifold
Reed valv
e
Gasket reed
valve)
3. Remove:
Piston
pin clip D
N
OTE
Before removing
piston
pin
c
irclip,
cover
crankcase
with ac lean ra
g to preve
nt circlip
fr o
m
fal l in
g intocrankcase
ca vity.
l
4.
R
emove:
Piston p
in
Piston
Small
end
be
ar ing
NOTE
Befo
re removing
th e
piston pin, d
ebar
the
clip gr
ooved and p in h
o le area.
If th
e
piston
pin groo
ve is debarred
an
d piston pin i
s
s
till
d
ifficult to rem
ove, use p
iston pin pu l ler .
I
iston
pinpuller:
'
YU 01304
t r o m :
_
4 5
Do not use a ha
mme r todriv
e the pis ton p
in
out.
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E
NG
JNE
DISA
SS
EMB
LY
I
N
G
I
I
YB14
2 2
C
LUT
CH
ND
P RIM
R
Y DR
IV E
GE
R
N
O T
E
Wit
h the
eng
in emou
nted
,
the
clutc
h
and
pr i
-
mary
dr iv
e ge
ar c
an b
e
m
ainta
ined
b
y
r
emo-
v
ing th
efo l
lowin
g
parts
.
Aut
olube
pum
pc
able
and
hos
es
1.
R
emo
ve:
Ki
ckcra
nk
D
Cra
nkc
aseco
ver
(r ig
ht)
2 R
emo
ve :
B
olts
(pre
ssur
e
pla te
)
D
Y
S
pring
s(pr
essu
re
p la te
)
4-
6
3.Re
mov
e:
Pres
sure
p
late
D
Frict
ion
pla
te
C
lutc
hd
amp
er
C
lutc
h plat
e
Pus
h rod
1
B a
ll
P
ush
ro
d 2
j)
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ENGINE DISASSEMBLY
E N G ~ ~ ~
4 7
4.
Remove:
Nut clutch boss)
D
Conical spring
washer
Clutch boss
Thrust
washer
Use
the
universal
clutch
holder to hold
the clutch boss.
Universal clutch holder
YM 91042
5
Remove:
Clutch
housing D
Spacer
Thrust washer
6. Remove:
Nut primary
drive
gear)
Conical spring
washer
NOTE
When
loosing
the
nut primary drive gear),
hold the COl magneto using universal rotor
holder.
Universal rotor holder
YU 01235
7. Remove:
Primary drive
gear D
Straight key
Collar
YB142003
KICK
AXLE
NOTE
With
the
engine
mounted, the kick
axle and
kick
idle gear can be maintained
by
removing
the
following parts.
Autolube pump cable and hoses
Crankcase cover right)
Clutch
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ENGINE DIS SSEMBLY
NG
4-8
1.
Unhook the
spring D .
2. Remove:
Kick
axle assembly
3. Remove:
Circlips D
Washers
Kick
idle gear
YB142004
SHIFT SH FT
NOTE
With
the
engine
mounted, the shift shaft
can
be maintained
by removing the following
parts.
Autolube pump
cable and hoses
Crankcase cover right)
Clutch
1. Remove:
Change pedal shaft cover
D
Dowel
pins
2. Remove:
Circlip
D
Change pedal lever
Collar change pedal
shaft
Change pedal
shaft
Washers
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_N_G
_IN_
e_o_ls
_ _s
_s_e_
M_B_
Lv_l
NG
_
4-9
3 . R e
m ov
e :
Shi f
t sh
aft D
Shif t
lev
er
YB 14200
5
C
Ol M G
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