Starter Does Not Operate or Does Not Turn Engine Over
  1. Engine OFF/RUN switch off.
  2. Discharged battery or loose or corroded connections (solenoid chatters).
  3. Clutch lever not squeezed against handlebar or transmission not in neutral.
  4. Jiffy stand not in retracted position (for models equipped with jiffy stand interlock).
  5. Blown fuse.
Engine Turns Over But Does Not Start
  1. Fuel tank empty.
  2. Fuel filter clogged.
  3. Discharged battery or loose or damaged battery terminal connections.
  4. Fouled spark plugs.
  5. Spark plug cable connections loose or in bad condition and shorting.
  6. Loose or corroded wire or cable connection at coil or battery.
  7. Fuel pump inoperative.
  8. Blown fuse.
Starts Hard
  1. Spark plugs in bad condition, have improper gap or are partially fouled.
  2. Spark plug cables in bad condition and leaking.
  3. Battery nearly discharged.
  4. Loose wire or cable connection at one of the battery terminals or at coil.
  5. Engine oil too heavy (cold weather).
  6. Fuel tank vent plugged or fuel line closed off, restricting fuel flow.
  7. Water or dirt in fuel system or filter.
  8. Fuel pump inoperative.
Starts But Runs Irregularly or Misses
  1. Spark plugs in bad condition or partially fouled.
  2. Spark plug cables in bad condition and leaking.
  3. Spark plug gap too close or too wide.
  4. Battery nearly discharged.
  5. Damaged wire or loose connection at battery terminals or coils.
  6. Intermittent short circuit due to damaged wire insulation.
  7. Water or dirt in fuel system or filter.
  8. Fuel vent system plugged. See dealer.
  9. One or more injectors fouled.
A Spark Plug Fouls Repeatedly
  1. Fuel mixture too rich.
  2. Incorrect spark plug for service
Pre-ignition or Detonation (Knocks or Pings)
  1. Incorrect fuel.
  2. Incorrect spark plug for service
Overheats
  1. Insufficient oil supply or oil not circulating.
  2. Heavy carbon deposit from lugging engine. See dealer.
  3. Insufficient air flow over cylinder heads during extended periods of idling or parade duty.
Excessive Vibration
  1. Rear fork pivot shaft loose. See dealer.
  2. Front engine mounting bolts loose. See dealer.
  3. Front chain or links tight as a result of insufficient lubrication or belt badly worn.
  4. Engine to transmission mounting bolts loose (applicable models). See dealer.
  5. Damaged frame. See dealer.
  6. Wheels and/or tires damaged. See dealer.
  7. Vehicle not properly aligned. See dealer.
Engine Oil Not Circulating (Oil Pressure Lamp Lit)
  1. Insufficient or diluted oil supply.
  2. Oil feed clogged with ice and sludge in freezing weather.
  3. Grounded oil signal switch wire or faulty signal switch. See dealer.
  4. Damaged or improperly installed check valve. See dealer.
  5. Oil pump problem. See dealer.