19
NO
NO
Troubleshooting Guide
Does the engine crank?
Good compression?
Does the tank contain fresh fuel
of the proper grade?
Is fuel visible and moving in the
return line when priming?
Is there spark at the spark plug
wire terminal?
Check the spark plug.
Faulty recoil starter.
Fluid in the crankcase.
Internal damage.
Loose spark plug.
Excess wear on cylinder, piston, rings.
Valves not seating.
Fuel incorrect, stale, or contaminated;
mixture incorrect.
Check for clogged fuel filter and/or vent.
Priming pump not functioning properly.
The ignition switch is in “O” (OFF) position.
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.
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
JASO FC classified oils at 50:1 gasoline/oil ratio.
Replace fuel filter or vent as required. restart.
Consult with an authorized servicing dealer.
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 - 0.7 mm. Restart.
Replace the plug with an NGK CMR5H or equivalent
resistor type spark plug of the correct range. Set
spark plug electrode gap to 0.6-0.7 mm.
NO
YES
What To Check
Possible Cause
Remedy
ENGINE DOES NOT START
NO
YES
NO
YES
YES
NO
YES
Is the engine overheating?
Engine is rough at all speeds.
May also have black smoke an/
or unburned fuel at the exhaust.
Operator is overworking the unit.
Carburetor mixture is too lean.
Improper fuel ratio.
Fan, fan cover, cylinder fins dirty or damaged.
Carbon deposits on the piston or in the muffler.
Clogged air cleaner element.
Loose or damaged spark plug.
Air leakage or clogged fuel line.
Water in the fuel.
Piston seizure.
Faulty carburetor and/or diaphragm.
Valve clearance set incorrectly.
Overheating condition.
Improper fuel.
Carbon deposits in the combustion chamber.
Valve clearance set incorrectly.
Shorten trimmer line. Cut at a slower rate.
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
JASO FC classified oils at 50:1 gasoline/oil ratio.
Clean, repair or replace as necessary.
Consult with an authorized servicing dealer.
Service the air cleaner element.
Tighten or replace.
Repair or replace fuel filter and/or fuel line.
Replace the fuel. See page 11.
Consult with an authorized servicing dealer.
See above.
Check fuel octane rating; check for presence of
alcohol in the fuel (page 11). Refuel as necessary.
Consult with an authorized servicing dealer.
What To Check
Possible Cause
Remedy
LOW POWER OUTPUT
Engine is knocking.
