Maintenance
Diagnosis
Is the engine overheating?
Engine is rough at all speeds. May also
have black smoke an/ or unburned fuel at
the exhaust.
Engine is knocking.
Low power output
Cause
Operator is overworking the
unit.
Carburettor mixture is too lean.
Improper fuel ratio.
Fan, fan cover, cylinder fins
dirty or damaged.
Carbon deposits on the piston
or in the silencer.
Clogged air cleaner element.
Loose or damaged spark plug.
Air leakage or clogged fuel line.
Water in the fuel.
Piston seizure.
Faulty carburettor and/or dia-
phragm.
Valve clearance set incorrect-
ly.
Overheating condition.
Improper fuel.
Carbon deposits in the com-
bustion chamber.
Valve clearance set incorrect-
ly.
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Solution
Shorten trimmer line. Cut at a
slower rate.
Consult your dealer
Refill with fresh, clean unleaded
gasoline with a pump octane of 89
or higher mixed with a 2-cycle air
cooled mixing oil that meets or ex-
ceeds ISO-L-EGD and/or JASO
FC, FD classified oils at 50:1 gas-
oline/oil ratio.
Clean, repair or replace as neces-
sary.
Consult your dealer
Service the air cleaner element.
Tighten or replace.
Repair or replace fuel filter and/or
fuel line.
Replace the fuel.
Consult your dealer
See above.
Check fuel octane rating; check for
presence of alcohol in the fuel. Re-
fuel as necessary.
Consult your dealer