4-1 Troubleshooting
4-1-1 Starting difficult
TROUBLE
Normal
Something
spark
wrong with
plug
the fuel
spark
system
Normal
cylinder
com-
pression
Normal
high-ten-
sion line
spark
Normal
fuel
supply
system
High-
tension line
no spark
TROUBLE
Abnormal
Normal fuel
cylinder
supply sys-
compres-
tem
sion
* If still can't starting, have the engine to our authorized dealer for repair.
IV. DISASSEMBLING AND SERVICING
Fuel supply
is not
smooth or
no fuel
supply.
Fuel supply
is normal.
Spark plug
is in bad
conditions.
Normal
spark plug
Normal ignition
system
CAUSE
There is no enough fuel in fuel
tank and fuel cock is closed.
Air vent in the fuel filler cap
is clogged.
Improper or clogged main oil
flow hole.
Needle valve is not closed
properly or start hole is
clogged.
Float is damaged or sticking. Repair float.
Fuel is too filthy or deterio-
rated.
There is water in fuel.
Too much fuel in engine
Wrong fuel brand
Too much carbon deposit
and dirt around electrodes.
Electrodes are burn dam-
aged seriously or insulators
damaged.
Improper electrodes gap
High-tension line is damaged. Replace.
Ignition coil is damaged.
Magneto loses magnetism.
Abnormal gap between the
ignition coil and flywheel
CAUSE
Piston ring is worn to or even
over its wear limit.
Piston ring is broken.
Piston ring is sticking.
Spark plug is not tightened
or without a gasket.
Air leakage between cylinder
block and cylinder cover
Air leakage in the valves
20
4-1 Troubleshooting
REMEDY
Fill fuel, open fuel cock.
Dredge air vent.
Readjust or clean, blow to get
through.
Dismantle needle valve and
repair, clean, blow to get
through.
Replace.
Replace.
Drain extra fuel, dry up spark
plug electrodes.
Select proper fuel brand corre-
sponding with the requirements.
Clear away.
Replace spark plug.
Adjust to proper value.
Replace.
Replace.
Adjust gap.
REMEDY
Replace.
Replace.
Clear up carbon deposits.
Tighten with a gasket in.
Check cylinder gasket, and the
flatness of the surface by which
cylinder block contacting with
cylinder cover.
Tighten cylinder cover bolts in stip-
ulated order to stipulated torque.
Check valve. Clearance and
tightness, repair if necessary.