91
Troubleshooting
Problem: Spark absent or weak
Condition
Remedy
1.
Ignition coil
defective
2.
Spark plug
defective
3.
Magneto
defective
4.
CDI unit
defective
5.
Pick-up coil
defective
1. Replace ignition coil
2. Replace plug
3. Replace magneto
4. Replace CDI unit
5. Replace pick-up coil
Problem: Spark plug fouled with carbon
Condition
Remedy
1.
Mixture
too rich
2.
Idling RPM
too high
3.
Gasoline
incorrect
4.
Air cleaner element
dirty
5.
Spark plug
incorrect (too cold)
6.
Valve seals
cracked - missing
7.
Oil rings
worn - broken
1. Adjust carburetor
2. Adjust carburetor
3. Change to correct gasoline
4. Clean element
5. Replace plug
6. Replace seals
7. Replace rings
Problem: Spark plug electrodes overheat or burn
Condition
Remedy
1.
Spark plug
incorrect (too hot)
2.
Engine
overheats
3.
Spark plug
loose
4.
Mixture
too lean
1. Replace plug
2. Service cooling system
3. Tighten plug
4. Adjust carburetor
Problem: Magneto does not charge
Condition
Remedy
1.
Lead wires/connections
shorted - loose - open
2.
Magneto coils
shorted - grounded - open
3.
Regulator/rectifier
defective
1. Repair - replace - tighten lead wires
2. Replace magneto coils
3. Replace regulator/rectifier
Problem: Magneto charges, but charging rate is below the specification
Condition
Remedy
1.
Lead wires
shorted - open - loose (at terminals)
2.
Stator coils (charging)
grounded - open
3.
Regulator/rectifier
defective
4.
Cell plates (battery)
defective
1. Repair - tighten lead wires
2. Replace stator coils
3. Replace regulator/rectifier
4. Replace battery
Problem: Magneto overcharges
Condition
Remedy
1.
Internal battery
short circuited
2.
Regulator/rectifier
defective
3.
Regulator/rectifier
poorly grounded
1. Replace battery
2. Replace regulator/rectifier
3. Clean - tighten ground connection
Problem: Charging unstable
Condition
Remedy
1.
Lead wire
intermittently shorting
2.
Magneto
internally shorted
3.
Regulator/rectifier
defective
1. Replace lead wire
2. Replace magneto
3. Replace regulator/rectifier
Problem: Starter button not effective
Condition
Remedy
1.
Battery charge
low
2.
Switch contacts
defective
3.
Starter motor brushes
not seating
4.
Starter relay
defective
5.
Emergency stop - ignition switch
off
6.
Wiring connections
loose - disconnected
7.
Starter bushings
worn
8.
Starter armature
shorted - open
9.
Brake switch
defective
1. Recharge - replace battery
2. Replace switch
3. Repair - replace brushes
4. Replace relay
5. Turn on switches
6. Connect - tighten - repair connections
7. Replace starter
8. Replace starter
9. Replace switch
Problem: Battery “sulfation” (Acidic white powdery substance or spots on surfaces of cell plates)
Condition
Remedy
1.
Charging rate
too low - too high
2.
Specific gravity
too low
3.
Battery
run-down - damaged
4.
Electrolyte
contaminated
1. Replace battery
2. Charge battery
3. Replace battery
4. Replace battery