| 1) Firing incorrect: |
Spark plug dirty, broken, or maladjusted
Spark plug cap or high tension wiring trouble
Spark plug cap short or not in good contact
Spark plug incorrect
Pickup coil trouble
CDI unit trouble
Ignition coil trouble
|
| 2) Fuel/air mixture
incorrect: |
Main jet clogged or wrong size
Jet needle or needle jet worn
Fuel level too high or too low
Air cleaner clogged, poorly sealed, or missing
Choke valve stuck open
Water or foreign matter in fuel
Carburetor holder loose
Air cleaner duct loose fuel tank air vent obstructed
Fuel tap clogged
Fuel line clogged
|
| 3) Compression low: |
Refer A - 3
|
| 4) Knocking: |
Carbon built up in combustion chamber
Fuel poor quality or incorrect
Spark plug incorrect
|
| 5) Miscellaneous: |
Throttle valve won’t fully open
Throttle valve doesn’t slide smoothly
Brakes dragging
Clutch slipping
Overheating
Engine oil level too high
Engine oil viscosity too high
|
