Starter Does Not Operate or Does Not Turn Engine Over
  1. Engine run switch in OFF position.
  2. Ignition switch not ON.
  3. Discharged battery or loose or corroded connections (solenoid chatters).
Engine Turns Over But Does Not Start
  1. Fuel tank empty.
  2. Fuel vacuum line disconnected.
  3. Fuel valve or filter clogged.
  4. Discharged battery or loose or broken battery terminal connections.
  5. Fouled spark plugs.
  6. Spark plug coil connections loose or in bad condition and shorting.
  7. Loose or corroded wire or cable connection(s) at coil or battery.
  8. Fuel pump inoperative.
Starts Hard
  1. Spark plugs in bad condition, have improper gap, or are partially fouled.
  2. Battery nearly discharged.
  3. Loose wire or cable connection(s) at one of the battery terminals or at coil.
  4. Engine oil too heavy (winter operation).
  5. Fuel tank vent plugged or fuel line closed off, restricting fuel flow.
  6. Water or dirt in fuel system.
  7. Fuel pump inoperative.
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. Battery nearly discharged.
  4. Damaged wire or loose connection at battery terminals or coils.
  5. Intermittent short circuit due to damaged wire insulation.
  6. Water or dirt in fuel system, filter or carburetor.
  7. Fuel vent system plugged. See dealer.
  8. One or more injectors fouled.
A Spark Plug Fouls Repeatly
  1. Incorrect spark plug.
Pre-ignition or Detonation (Knocks or Pings)
  1. Incorrect fuel.
  2. Incorrect spark plug for the kind of service.
  1. Insufficient oil supply or oil not circulating.
  2. Heavy carbon deposit from lugging engine. See dealer.
Excessive Vibration
  1. Rear fork pivot shaft nuts loose. See dealer.
  2. Front engine mounting bolts loose. See dealer.
  3. Broken frame. See dealer.
  4. Belt badly worn.
  5. Wheels and/or tires damaged. See dealer.
  6. Vehicle not properly aligned. See dealer.