-4-
Piston ring is damaged.
Replace.
Piston or cylinder is stuck.
Replace.
Needle bearing on connecting rod is damaged.
Replace.
Ball bearing is stuck.
Replace.
Magneto rotor touches the ignition coil.
Inspect and
adjust.
Recoil starter is damaged.
Inspect and
replace.
Valve is damaged.
Replace.
Oil pump (inner or outer rotor) is damaged.
Replace.
Crank gear or cam gear is damaged.
Replace.
Stop switch is not set to starting position.
Set switch to
start position.
Spark plug is stained or faulty.
Clean and
inspect.
High-voltage cord or other cable broke, or its
connection is faulty.
Inspect.
High-voltage cord or other cable is grounded.
Inspect.
Ignition coil broke or is faulty.
Replace.
Clearance between magneto rotor and ignition
coil is too large.
Adjust.
Fuel filter (pump filter body assembly) was
clogged.
Clean or
replace.
Fuel pipe is cracked or creased.
Replace.
Air hole on tank cap is faulty.
Replace.
Pump diaphragm of carburetor is faulty.
Replace.
Carburetor is clogged with foreign matter.
Clean.
Piston ring is faulty.
Replace.
Piston ring is worn.
Replace.
Piston is worn.
Replace.
Cylinder is worn.
Replace.
Cam is damaged.
Replace.
Crank gear or cam gear is damaged.
Replace.
Valve is damaged.
Replace.
Carbon accumulated on a sealed valve surface.
Clean.
Fuel filter (pump filter body assembly) is clogged.
Clean or
replace.
Warm-up is insufficient especially in a cold
environment.
Warm up.
Valve clearance is extended.
Inspect and
adjust.
OK
NG
OK
NG
The engine stalls
Pull the starter handle.
Check whether there is
compression and the handle can
be pulled.
The engine starts.
Pull the throttle lever, and check
what happens.
NG
OK
Check whether there is
compression.
OK
OK
NG
Remove the spark plug.
Check whether the plug sparks.
Mount the spark plug and spark
plug cap, and perform correct
startup operation.
Check whether the spark plug
head is wet with fuel.
Repair flowchart
