Troubleshooting Guide
What To Check
Vaporlock.
Valve adjustment.
What To Check
Does the engine crank?
YES
Good compression?
YES
Does the tank contain fresh fuel
of the proper grade?
YES
Is fuel visible and moving in the
return line when priming?
YES
Is there spark at the spark plug
wire terminal?
YES
Check the spark plug.
16
ENGINE DOES NOT START OR HARD TO START
Possible Cause
Engine hot/heat soaked.
Low fuel quality.
Valve clearance too tight.
Valve clearance too loose.
ENGINE DOES NOT START
Possible Cause
NO
Faulty recoil starter.
Fluid in the crankcase.
Internal damage.
NO
Loose spark plug.
Excess wear on cylinder, piston, rings.
NO
Fuel incorrect, stale, or contaminated;
mixture incorrect.
NO
Check for clogged fuel filter and/or vent.
The ignition switch is in "O" (OFF) position.
NO
Shorted ignition ground.
Faulty ignition unit.
If the plug is wet, excess fuel may
be in the cylinder.
The plug is fouled or improperly gapped.
The plug is damaged internally or
of the wrong size.
Remedy
Let cool completely and restart.
Refill with fresh, clean unleaded gasoline with a pump
octane of 87 or higher mixed with a 2-cycle air cooled
mixing oil that meets or exceeds ISO-L-EGD and/or
JASCO FC classified oils at 50:1 gasoline/oil ratio.
Adjust valves. See page 14.
Remedy
Consult with an authorized servicing dealer.
Tighten and re-test.
Consult with an authorized servicing dealer.
Refill with fresh, clean unleaded gasoline with a pump
octane of 87 or higher mixed with a 2-cycle air cooled
mixing oil that meets or exceeds ISO-L-EGD and/or
JASCO FC classified oils at 50:1 gasoline/oil ratio.
Clean as required. Restart.
Move switch to "I" (ON) position and re-start.
Consult with an authorized servicing dealer.
Crank the engine with the plug removed, reinstall the
plug, and restart.
Clean and regap the plug to 0.6 - 0.7mm. Restart.
Replace the spark plug with a NGK CMR5H or
equivalent spark plug of the correct heat range.
Adjust the spark plug electrode gap to 0.6 - 0.7 mm.