Vento Phantom R4i - Electrical Troubleshooting

VENTO MOTORCYCLES
Rev no.01/ page 84of 84
ELECTRICAL
Complaint Symptom and possible causes Remedy
No sparking or
poor sparking.
1. Defective CDI & ignition coil unit.
2. Defective spark plug.
3. Defective magneto stator coil.
4. Loose connection of lead wire.
5. Defective pick-up coil
Replace.
Replace.
Replace.
Connect/tighten.
Replace.
Spark plug
soon becomes
fouled with
carbon.
1. Mixture too rich.
2. Idling speed too high.
3. Incorrect gasoline.
4. Dirty element in air cleaner.
5. Spark plug loose.
6. Too cold spark plugs
Adjust carburetor.
Adjust carburetor.
Change & use specified gasoline.
Clean.
Check & retighten.
Replace with hot type plugs.
Spark plugs
become fouled
too soon
1. Worn piston rings.
2. Worn piston or cylinder.
3. Excessive clearance of valve stems in valve
guides.
4. Worn stem oil seals.
Replace.
Replace.
Replace.
Replace.
Spark plug
electrodes
overheat or
burn.
1. Spark plug too hot.
2. Overheated the engines
3. Loose spark plugs.
4. Too lean mixture.
5. Not enough engine lubricating oil.
Replace with specified cold plugs.
Tune up.
Retighten.
Adjust carburetor.
Check oil pump.
Magneto does
not charge the
battery.
1. Open or short in lead wires, or loose lead
connections.
2. Shorted, grounded or open magneto coil.
3. Shorted or open regulator/rectifier.
Repair or retighten.
Replace.
Replace.
Magneto
charge, but
charging rate is
below the
specifications.
1. Lead wires tend to get shorted or open-circuited
or loosely connected at terminal.
2. Grounded or open-circuited stator coils of
magneto.
3. Defective regulator/rectifier.
4. Defective cell plates in the battery,
Repair or retighten.
Replace.
Replace.
Replace the battery.
Magneto
overcharges.
1. Internal short-circuit in the battery.
2. Resistor element in the regulator/rectifier
damaged or defective.
3. Regulator/rectifier unit poorly grounded.
Replace the battery.
Replace.
Clean and tighten ground
connection.