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TROUBLESHOOTING
8-2
EAS28490
INCORRECT ENGINE IDLING SPEED
Engine
1. Cylinder and cylinder head
• Incorrect valve clearance
• Damaged valve train components
2. Air filter
• Clogged air filter element
• Loosen air filter joint
Fuel system
1. Carburetor
• Faulty starter plunger
• Loose or clogged pilot jet
• Loose or clogged pilot air jet
• Damaged or loose carburetor joint
• Improperly adjusted engine idling speed
(throttle stop screw)
• Improper throttle cable free play
• Flooded carburetor
Electrical system
1. Battery
• Discharged battery
• Faulty battery
2. Spark plug
• Incorrect spark plug gap
• Incorrect spark plug heat range
• Fouled spark plug
• Worn or damaged electrode
• Worn or damaged insulator
• Faulty spark plug cap
3. Ignition coil
• Broken or shorted primary or secondary
coils
• Faulty spark plug lead
• Cracked or broken ignition coil
4. Ignition system
• Faulty CDI unit
• Faulty pickup coil
• Broken generator rotor woodruff key
EAS28510
POOR MEDIUM-AND-HIGH-SPEED PER-
FORMANCE
Refer to “STARTING FAILURES” on page 8-1
and “INCORRECT ENGINE IDLING SPEED”
on page 8-2.
Engine
1. Air filter
• Clogged air filter element
Fuel system
1. Carburetor
• Faulty diaphragm
• Incorrect fuel level
• Loose or clogged main jet
• Improper jet needle clip position
• Deteriorated or contaminated fuel
EAS28530
FAULTY GEAR SHIFTING
Shifting is difficult
Refer to “Clutch drags”.
EAS28540
SHIFT PEDAL DOES NOT MOVE
Shift shaft
• Improperly adjusted shift rod
• Bent shift shaft
Shift drum and shift forks
• Foreign object in a shift drum groove
• Seized shift fork
• Bent shift fork guide bar
Transmission
• Seized transmission gear
• Foreign object between transmission gears
• Improperly assembled transmission
EAS28550
JUMPS OUT OF GEAR
Shift shaft
• Incorrect shift pedal position
• Improperly returned stopper lever
Shift forks
• Worn shift fork
Shift drum
• Incorrect axial play
• Worn shift drum groove
Transmission
• Worn gear dog
EAS28570
FAULTY CLUTCH
Clutch slips
1. Clutch
• Improperly assembled clutch
• Loose or fatigued clutch spring
• Worn friction plate
• Worn clutch plate
2. Engine oil