-2-
Problem
Cause
Corrective action
Starts, but when
it accelerates…
The engine stalls.
The fuel filter is clogged.
Clean or replace the part.
Valve
clearance is
extended.
Loose nuts
Repair the parts.
Worn push rod
Replace the faulty part.
Poor acceleration;
no increase in rpm
Worn valve
Worn pivot
Worn rocker arm
Worn tappet
The muffler is clogged with
carbon.
Clean the part.
The air cleaner is clogged.
Carbon accumulated on a valve.
Starts, but …
Fluctuating rpm at
high speed
The carburetor is clogged with
foreign matter.
Clean the part.
Excessive fuel
consumption
The air cleaner is clogged.
Clean the part.
Chain oil is not discharged.
The piston ring is worn.
Replace the faulty part.
The cylinder is worn.
The piston is deformed.
The oil seal is worn or damaged.
