34
Troubleshooting Guide
(continued)
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 machine.
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 JASCO 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.
Tighten or replace.
Repair or replace filter and/or fuel line.
Replace the fuel.
Consult with an authorized servicing dealer.
See above.
Check fuel octane rating; check for presence of
alcohol in the fuel (pg. 15). Refuel as necessary.
Consult with an authorized servicing dealer.
What To Check
Possible Cause
Remedy
LOW POWER OUTPUT
Engine is knocking.
