No sparking or poor sparking
Defective ignition coils or spark plug caps. | Replace. |
Defective spark plugs. | Replace. |
Defective CKP sensor. | Replace. |
Defective ECM. | Replace. |
Defective TO sensor. | Replace. |
Open-circuited wiring connections. | Check and repair. |
Spark plug soon become fouled with carbon
Mixture too rich. | Inspect Fl system. |
Idling speed set too high. | Adjust fast idle or throttle stop screw. |
Incorrect gasoline. | Change. |
Dirty air cleaner element. | Clean or replace. |
Too cold spark plugs. | Replace with hot type plugs. |
Spark plug become fouled too soon
Worn piston rings. | Replace. |
Worn piston or cylinders. | Replace. |
Excessive clearance of valve stems in valve guides. | Replace. |
Worn stem oil seal. | Replace. |
Spark plug electrodes overheat or burn
Too hot spark plugs. | Replace with cold type plugs. |
Overheated the engine. | Tune up. |
Loose spark plugs. | Retighten. |
Too lean mixture. | Consult Fl system. |
Generator does not charge
Open- or short-circuited lead wires, or loose lead connections. | Repair or replace or retighten. |
Short-circuited, grounded or open generator coil. | Replace. |
Short-circuited or punctured regulator/rectifier. | Replace. |
Generator does charge, but charging rate is below the specification
Lead wires tend to get short- or open-circuited or loosely connected at terminals. | Repair or retighten. |
Grounded or open-circuited generator coil. | Replace. |
Defective regulator/rectifier. | Replace. |
Defective cell plates in the battery. | Replace the battery. |
Generator overcharges
Internal short-circuit in the battery. | Replace the battery. |
Damaged or defective resistor element in the regulator/rectifier. | Replace. |
Poorly grounded regulator/rectifier. | Clean and tighten ground connection |
Unstable charging
Lead wire insulation frayed due to vibration, resulting in intermittent short-circuiting. | Repair or replace. |
Internally short-circuited generator. | Replace. |
Defective regulator/rectifier. | Replace. |
Starter button is not effective
Run down battery. | Repair or replace. |
Defective switch contacts. | Replace. |
Brushes not seating properly on starter motor commutator. | Repair or replace. |
Defective starter relay/starter interlock switch. | Replace. |
Defective main fuse. | Replace. |