3-55
ENG
TROUBLESHOOTING
ENGINE SPEED IS UNEVEN
Check fuel level.
SUFFICIENT
INSUFFICIENT
Add.
Check if fuel is deteriorated.
GOOD
NO GOOD
Replace.
Check if fuel cock, fuel pipe, fuel
hose and fuel pipe strainer are
clogged.
GOOD
NO GOOD
Clean.
Check spark plug for dirt and
check spark plug gap.
GOOD
NO GOOD
Clean or adjust.
Measure valve clearance.
GOOD
OUT OF SPECI-
FICATION
Adjust.
While the engine is operating, pull
the choke knob approximately 1/3
to 1/2 way out, and then check the
engine operating condition.
STABLE
UNSTABLE
Check for air suction due to a
damaged throttle shaft seal, car-
buretor joint, or gasket.
GOOD
NO GOOD
Disassemble or replace.
Check if slow or main passages
such as, the pilot jet and main jet,
in the carburetor are clogged.
GOOD
NO GOOD
Disassemble or clean.
Check valve face and valve seat
for wear.
GOOD
WEAR
Resurface or replace.
Check if there is seizure or wear
on the piston, piston ring, or cylin-
der.
GOOD
SEIZURE OR
WEAR
Rebore or replace.
Check the condition of the throttle
control system. Refer to “THROT-
TLE CONTROL SYSTEM”.
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