Troubleshooting Guide
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.
What To Check
Is the engine overheating?
Engine is rough at all
speeds. May also have
black smoke and/or
unburned fuel at the
exhaust.
Engine is knocking.
ENGINE DOES NOT START
Possible Cause
Faulty recoil starter.
NO
Fluid in the crankcase.
Internal damage.
Loose spark plug.
NO
Excess wear on cylinder, piston, rings.
Fuel incorrect, stale or contaminated;
NO
mixture incorrect.
Check for clogged fuel filter and/or vent.
NO
Priming pump not functioning properly.
The ignition switch is in "O" (OFF)
NO
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.
LOW POWER OUTPUT
Possible Cause
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.
Overheating condition.
Improper fuel.
Carbon deposits in the combustion
chamber.
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 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 restart.
Consult with an authorized servicing dealer.
Crank the engine with the plug removed,
reinstall the plug, and restart.
Clean and regap the plug to 0.024 - 0.028
inch (0.6 - 0.7 mm). Restart.
Replace the plug with an BPMR6A or
equivalent resistor type spark plug of the
correct heat range. Set spark plug electrode
gap to 0.024-0.028 inch (0.6-0.7 mm).
Remedy
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. Replace the plug with an
BPMR6A or equivalent resistor type spark plug
of the correct heat range.
Repair or replace filter and/or fuel line.
Replace the fuel. See page 9.
Consult with an authorized servicing dealer.
See above.
Check fuel octane rating; check for presence of
alcohol in the fuel (pg. 9). Refuel as necessary.
Consult with an authorized servicing dealer.
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