COOTER TROUBLE-SHOOTING & TUNE-UP S

PROCEDURES 2 Stroke & 4 Stroke Engines. A. It takes 3 things for an engine to run. 1. Fuel – Add a full tank of clean gas, 90 octane or higher. 2. Spark – Make sure the battery has a full charge and is reading 12-13.4 volts. 3. Compression If your engine does not run, then either the engine is not getting gas, spark, or compression, or a combination of them. It’s always best to run the scooter weekly. A scooter that is not used regularly will not run well. Even a brand new one. B. The 5 most common reasons why scooters don't run.

1. Fouled spark plug. (Fouled by fuel)

2. Ignition system. (Dead battery) 3. Fuel Flow (to the CARBURETOR)

4. Dirty carburetor (inside, old gummed up gas)

5. Kill Switch (Make sure the kill switch is on and the brake lever pulled in)

A dirty carburetor is the most common problem. B

ASIC TROUBLESHOOTING - follow these steps to get it to run

Fouled spark plug: The first thing to check on a scooter that won't run is to

park plugs in 2 strokes get "fouled" easily. This is mostly because of the oil that the

d

ull the old spark plug out and put a NEW spark plug in the cap and hold the metal

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2. Ignition system: If there is no spark, check the ignition system.

omposed of a CDI, Stator, Trigger coil, and Ignition

eck the voltage output of the stator and the trigger coil using a voltage meter. They be 60-120 VAC for the trigger and 15-40 ACV for the stator. Check for loose

or disconnected wiring. Replace the CDI if needed.

1.see if you have spark at the spark plug. Sengine burns. Fouled means the spark won't jump the gap. It won't jump the gap because there is a film of baked on gas and oil on the insulator, (the white ceramic part inside the plug) that allows the electrical energy to "bleed" off and run to grouninstead of jumping the gap. The spark plug might still look good, yet the spark still won't jump the gap. That is why if your engine quit running, or won’t start, it is smart to replace the plug and check for spark. Ppart of the plug firmly against the cylinder head while you engage the electric starter with the key and kill switch on. It will help to do this in a dark area to make it easier tsee the spark. Make sure you have a good spark plug to start with. A black, oily, or wet one will not spark.

The Ignition system is ccoil. Chshould

has some 2 stroke oil in it). If it starts and runs for 5 seconds and then dies, then check for fuel flow

Remove the fuel line going into the carburetor. (Remove Clip from fuel hose at ice, pull a vacuum on the fuel

etcock for approx. 1 minute. Fuel should be entering the petcock from the fuel tank).

logged or a dirty carburetor is the most common reason for poor

e d fuel passages), not the outside. USE COMPRESSED AIR (80psi) to

low it out. The carburetor must be removed. Take off the float bowl (on the bottom),

n count how many turns it takes to go all the ay in, such as 1 3/4 turns. Be sure to remember this number for later). Then remove

plastic parts first), and en blow it out with compressed air, making sure to clear out all the small orifices.

lly

e scooter is Still not running at all or correctly?

If there is spark, place a spoonful of fuel into the spark plug hole and try to start it. (Note: if it is a 2 stroke engine, make sure the gas

Carburetor.

3. Fuel Flow: FUEL FLOW to the CARBURETOR

petcock. Using a simple vacuum pump or any suction devpIf no fuel flow, you must take the petcock off and replace it.

If you have fuel flow to the carburetor and spark at the plug and it still won't run, then the carburetor should be cleaned.

4. Dirty carburetor: CLEANING the CARBURETOR Cperformance. a. The parts of the carburetor that are dirty or clogged are the small holes inside thcarburetor (air anband then remove the brass "main jet" in the middle of the carburetor and blow air through it. Hold it up to a light and look through it. It must be clean and clear. If it is not clear you must clean it with a Jet cleaner. A small piece of wire may be used instead of jet cleaner, but be careful. b.Next you should screw the idle mixture screw in, (Note: Before you screw it in, look at where the screwdriver slot is at, thewall the screws being careful to note where everything goes. c. Next the carburetor should be thoroughly cleaned. Submerge the carburetor overnight in a can of carburetor cleaner (remove rubber andthThen reassemble all the parts and reinstall the carburetor. Note: Remember to turn the idle mixture screw back out to its original setting, usuabetween 1 and 2 full turns out from all the way in. Note: Using fuel stabilizer, such as Opti-Mizer, will help to keep the carburetor clean. f th Have you installed a brand new spark plug? I

Have you tested the ignition system? Have you Checked for fuel flow to the carburetor? Have you thoroughly cleaned the carburetor?

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Additional steps to Service:

.Check if the Muffler is clogged with carbon. carbon.

. Check if the Rings, Piston, or Cylinder are worn out or damaged and don't ave enough compression.

tor) is too dirty to flow air very

scooter that has a clogged muffler will usually start and run, but will not run ell or fast.

r goes a lot faster, then the muffler is probably clogged and hould be replaced. Cleaning the muffler can be difficult and dangerous.

pipe and look into the xhaust port (on the cylinder). You should be able to rotate the ignition flywheel with

n going up and down. If ou can't you need to remove the head and cylinder and thoroughly clean the exhaust

and

y scoring around the cylinder they will need to be replaced. If there is no

om the piston on the cylinder and even smeared melted aluminum over part of the

12. Check if the Exhaust port is clogged with 3h4. Check if the Air filter (going into the carburewell. 5. Check if the air filter is missing, and the engine is getting too much air. 6. Check if the Head gasket is leaking. 1. MUFFLER CLOGGED WITH CARBON Aw To test for a clogged muffler: Remove the muffler and run the scooter without the muffler. If your scoote s 2. EXHAUST PORT IS CLOGGED WITH CARBON Same as a clogged muffler, it will run but not very fast. To check for a clogged Exhaust Port, remove the exhausteyour hand while looking into the port and clearly see the pistoyport being extremely careful not to scratch the cylinder where the piston rides updown. 3. WORN OUT RINGS, PISTON, OR CYCLINDER (test for compression) The compression should be between 120 psi and 140 psi, if not check the following: Look for scuffing and scoring around the cylinder and piston skirt. If there is heavscuffing andscuffing and scoring, check for evidence of a seizure. If there is smeared aluminum frrings, then these parts need to be replaced. If the scooter has over 3000 miles on it with the original rings, new rings should be installed. INSTALLING PISTON and RINGS CORRECTLY

Aeinserted one way. It should have an arrow on the top, wth Rings are usually (but not always) supposed to be installed letter side up(towards tspark plug). If they don't have small letters on them, look closely at the ring ends anthe type of pin they have to see how they mat Next, locate the ring end gaps correctly on the piston. Look closely in the piston ring grooves. You should see a small pin in the groove. The ring ends go right at those pins. (Note: If you have 2 rings the pins are NOT in the sa The difficult part often is compressing the rings with your fingers while keeping them the right location (at the pins), while sliding the cylinder on to the piston. 4&5. AIR FILTER Eaor too much oil, it wfo Foam air filters can be cleaned in gasoline and allowed to dry, then LIGHTLY oiled. (Spread only a light coating of oil around). Paper Air filters can be blown off with compressed air or shoul Warning: Running the engine with no air filter can cause the engine to get too much air and lean out, and possibly seize. 6. First, the head nuts should be tight Loosen all the head nuts, then tigthpounds (for a 6mm thread size) with a torque wrench.

ll parts must be cleaned very carefully before you service and rebuild a new “top nd”. Cover the piston and cylinder with new 2-stroke oil. The piston may only be

hich is supposed to point at e exhaust port (away from the carburetor).

he d

e together.

me location for both)

in

ngines are designed to run with air filters to keep dirt out so that the piston nd rings and cylinder will last a long time. If the air filter gets clogged with dirt

ill richen up the air/fuel ratio and slow it down, and possibly ul the spark plugs.

d be replaced. Never use oil on a paper Air filter.

LEAKING HEAD GASKET

ened correctly.

hten each bolt or nut a ¼ turn in an X pattern until ey are all tight. Torque setting: tighten in 3 increments (3-6-9lbs) for 9 foot

ead

aces of oot on the surfaces of the gasket or head or cylinder.

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NGINE TUNING

If you have a leak you can sometimes hear compression squeezing out past the hgasket. Check closely between the cylinder and head to see if it is oily. Oil usually indicates a leak. You can also remove the head and gasket and look for black trs Note: Head gaskets on 2 stroke scooters are made of metal (usually aluminum ocopper). Metal head gaskets can be reused as long as there isn’t any damage.

TUNE-UP PROCEDURES E

A. Examining SPARK PLUGS Two stroke engines are ssiopen throttle. Too “hot” and they will seize the piston. Too “cool” and they will not make full power. Engines get theHP. Examining a spark plug is the best way toExamining the plug means looking at the ceramic inchecking the color. The color will indicate the overall level of hea To examine the plug, fully warm up the engine by running it for about 10 minutes. Then run full throttle for 60 seconds and immediately cut the engine. Let the engineand plug cool, and remove the plug and begin the examination of the plug color. The color of a plug on a correctly running engine is a light brown or tcolor. a. A lighter color than that means danger of a piston seizure. bMain Jet in the carburetor is too big (too rich). Remove the main Jet and look at the number Note: To get an accurate plug reading takes a fairly new plug. Replace old or warn plugs. B There a 1. 1. Idle Mixture: Idle mixture co2.

little more airflow.

ensitive to the level of heat inside the engine. The main jet ze in the carburetor is the main determination of how hot the engine runs at wide-

hottest when they are running at wide open throttle making maximum see how hot the engine is running.

sulator inside the plug and t in the engine.

an

. A Darker color than that is acceptable, but real dark or wet looking means the

on the side and buy the next size smaller (leaner).

. ADJUSTING the CARBURETOR

re usually 2 external adjustments on the carburetor.

ntrols the air to fuel ratio (at idle). 2. Idle Speed screws: Idle speed usually opens the slide or butterfly for a

runs while going fast. Adjust the idle to be fast enough

ge leaner.

AS & OIL for TWO STROKES

Both adjustments only affect the engine idle, and do not affect how fast your scooter

es or how well the engine gonot to stall, but slow enough not to engage the transmission. Note: Idle mixture screws are usually set between 1 and 2 turns out from all the way in. Some carburetors with a slide have a needle in the middle of the slide with adjustment slots on the needle for raising or lowering the needle. Raising the needle

akes the mid-range richer. Lowering the needle makes the mid-ranm

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Most 49cc scooters have 2 stroke engines and must use oil in the fufor lubrication. 2 Stroke Scooters have a

el n auto-lube oil pump, so that

u don't have to pre-mix the gas and oil. Always check the oil

oir every time gas is added to scooter and keep it full.

Scooters engines operate best utilizing high octane (90) unleaded fuel. Use of rades of fuel may cause the engine to become damaged. Warning: Never leave fuel nk for long periods of time without treating it with fuel stabilizer. See below.

, because jets are so tiny that they get clogged easily. Fuel treatment will help the fuel that will clog these jets. It also removes any water that

mall carburetors, and can clog easily. Replace the fuel filter at regular filter has an ARROW molded into it, designating which direction

e gas is supposed to flow through it.

rvals or when the spark plus gets old, he correct size for the TNG engine model, go to the TNG web site

l data section or see the owners manual. Use only the plug that is

he batteries in scooters are very small and can become discharged very quickly, so it to connect them to a battery trickle charger when the scooter will not be eral days. If the scooter is not used weekly, put the charger on for 24

ended for that scooter.

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yoreservoir every time gas is added to the scooter and keep full. OIL lways use Opti 2 oil from CMSI to maintain the engine warranty. Check the oil A

reserv Fuel MSI C

lower gin the ta

Fuel stabilizer CMSI recommends to add Opti-Mizer brand fuel treatment to the fuelscooter carburetordissolve deposits inmight have entered into the fuel system. FUEL FILTER Scooters have sservice intervals. Theth SPARK PLUGS Replace the spark plugs at regular service intedirty, or warn. For tunder the technicarecommended for that scooter.

BATTERY Tis important sed for sevu

hours then disconnect, repeat process every 2 weeks. If the battery is not a sealed type, check water levels in the cells and add distilled water as needed. Never add more acid. For the correct battery size for the TNG model, go to the TNG web site under the technical data section or see the owner’s manual. Use only the battery size that is recomm LIMINATE PARTS FALLING OFF

To Stop fasteners from loosing up, use Loctite blue 242 on all fasteners when servicing. Set all structural fasteners to the proper torque setting.