Starter motor does not operate or does notturn engine over
1. Ignition switch not in ON position.
2. Engine run switch in OFF position.
3. Maxi-fuse not in place.
4. Discharged battery, loose or corroded connections (solenoid chatters).
5. Starter control circuit, relay, or solenoid faulty.
6. Electric starter shaft pinion gear not engaging or overrunning clutch slipping.
7. Crankshaft locking pin is in place.
Engine turns over but does not start
1. Fuel tank empty.
2. Fouled spark plugs.
3. Discharged battery, loose or broken battery terminal connections.
4. Engine lubricant too heavy (winter operation).
Note. For cold weather starts, always disengage clutch.
5. Loose wire connection at coil, battery, or plug between ignition module or ECM.
6. Ignition timing incorrect due to faulty coil, ignition module, ECM or sensors.
7. Bank Angle Sensor tripped and ignition switch not cycled OFF then ON.
8. Fuel filter clogged.
9. Sticking or damaged valve.
Starts hard
1. Spark plugs in bad condition or have improper gap or are partially fouled.
2. Battery nearly discharged.
3. Loose wire connection at one of the battery terminals, coil, or plug between ECM or ignition module.
4. Water or dirt in fuel system.
5. Intake air leak.
6. Fuel tank vent hose and vapor valve plugged, or fuel line closed off, restricting fuel flow.
7. Engine lubricant too heavy (winter operation).
Note. For cold weather starts, always disengage clutch.
8. Ignition not functioning properly (possible sensor failure).
9. Faulty ignition coil.
10. Valves sticking or valves too tight.
11. Rotor key sheared.
Starts but runs irregularly or misses
1. Spark plugs in bad condition or partially fouled.
2. Spark plug gap too close or too wide.
3. Faulty ignition coil, module, or sensor.
4. Battery nearly discharged.
5. Damaged wire or loose connection at battery terminals, coil, or plug between ignition sensor and module.
6. Intermittent short circuit due to damaged wire insulation.
7. Water or dirt in fuel system or filter.
8. Fuel tank vent system plugged or closed off.
9. Air leak at intake manifold or air filter.
10. MAP sensor inoperative.
11. Loose or dirty ignition module or ECM connector at crankcase.
12. Faulty Sensor(s): Manifold Absolute Pressure (MAP), or Crank Position (CKP).
13. Incorrect valve timing.
14. Weak or broken valve springs.
15. Damaged intake or exhaust valve.
A Spark plug fouls repeatedly
1. Fuel mixture too rich.
2. Incorrect spark plug for the kind of service.
3. Piston rings badly worn or broken.
4. Valve guides or seals badly worn.
Pre-lgnition or detonation (knocks or pings)
1. Fuel octane rating too low.
2. Faulty spark plugs.
3. Incorrect spark plug for the kind of service.
4. Excessive carbon deposit on piston head or in combustion chamber.
5. Ignition timing advanced due to faulty sensor inputs (MAP, CKP).
6. Air leak
Overheating
1. Insufficient oil supply or oil not circulating.
2. Insufficient air flow over engine.
3. Heavy carbon deposit.
4. Ignition timing retarded due to faulty sensor(s): Manifold Absolute Pressure (MAP) and/or Crank Position (CKP).
5. Leaking valve.
6. Radiator dirty, plugged.
7. Insufficient coolant supply.
8. Vent hose crimped.
9. Air in cooling system.
Valve train noise
1. Low oil pressure caused by oil feed pump not functioning properly or oil passages obstructed.
2. Valve sticking in guide.
3. Chain tensioning spring or shoe worn.
4. Cam timing incorrect.
5. Secondary cam tensioner out of range.
Excessive vibration
1. Wheels and/or tires worn or damaged.
2. Engine/transmission/rear wheel not aligned properly.
3. Upper engine mounting bracket loose/broken or mounting bracket pre-loaded.
4. Ignition timing advanced due to faulty sensor inputs (MAP, CKP)/poorly tuned engine.
5. Internal engine problem.
6. Broken frame.
7. Engine counterbalancer out of time or bearing failed.
8. Exhaust system binding or hitting frame.
Check engine light illuminates during operation
Fault detected. See the VRSCA Electrical Diagnostic Manual.