162 09/02
TROUBLESHOOTING
THE ENGINE DOES NOT START OR IT IS DIFFICULT TO START
Empty fuel tank.
Clogged fuel
intake pipe.
Clogged automatic starter fuel valve.
Clogged oil gallery.
Fuel cap suction hole.
Clogged fuel filter.
Clogged filter holder.
Fuel pump irregular operation.
Spark plug irregular operation.
Damaged spark plug.
CDI unit irregular operation.
AC generator irregular operation.
Ignition coil short circuit or failure.
Excitation coil short circuit
or failure.
Starter button irregular operation.
The starter motor is idling
but the crankshaft
does not rotate.
Small valve opening.
Incorrect valve running
along the seat.
Worn piston rings and
compression rings.
Burst cylinder upper gasket.
Defective cylinder head.
Starter button irregular operation.
Automatic starter irregular operation.
Air suction pipe irregular operation.
Wrong ignition time.
Incorrect adjustment of the main screw.
Flooded carburator.
Automatic starter irregular operation.
Throttle too open.
Check/adjustment
Problem
Possible cause
Start the engine as usual
Remove the spark plug and
check it again
Dry spark plug
Check cylinder compression
The plug sparks
Remove the spark plug and
check it again
Loose the drain screw to check
whether the fuel reaches the
carburator
1
2
3
4
5
6
7
8
The engine does not reach
the carburator
1
2
3
4
5
6
7
Weak spark or no spark
at all
1
2
3
4
5
6
7
8
1
2
3
4
Correct ignition but the
engine does not start
1
2
3
Wet spark plug
The engine does not start
Weak or no compression
at al
Normal compression
The engine reaches the
carburator
