Electrical system troubleshooting information (Aprilia RS 125/3, 3 generation, 1998-2005) [Information for owner: Troubleshooting]

Trouble	Symptom and possible causes	Remedy
Spark plugs develop exceeding carbon buildup too quickly	Carburetion too rich.	Adjust carburetor.
	Idling speed set too high.	Adjust carburetor.
	Fuel does not meet specification.	Change fuel.
	Air cleaner dirty.	Clean.
	Spark plug heat rating too low.	Replace with a higher rating spark plug.
Spark plugs become foul too quickly	Piston rings worn.	Replace.
Spark plugs become foul too quickly	Piston or cylinder worn.	Replace.
Spark plug electrodes overheated or burnt out	Spark plug heat rating too high.	Replace with lower rating spark plug.
	Engine overheats.	Adjust.
	Spark plug loose.	Tighten.
	Carburetion too lean.	Adjust carburetor.
Alternator does not charge battery	Connection terminals interrupted, shorted or loose.	Repair, replace or tighten.
	Generator coil shorted, discharging to earth or interrupted.	Replace.
	Regulator/rectifier shorted or faulty.	Replace.
Generator is undercharging the battery	Terminals have a tendency to short-circuiting, becoming interrupted or working themselves loose.	Repair or tighten.
	Generator stator coil discharging to earth or interrupted.	Replace.
	Regulator/rectifier faulty.	Replace.
	Faulty battery.	Replace.
Generator is overcharging the battery	Short circuit inside battery.	Replace the battery.
	Regulator/rectifier damaged or faulty.	Replace.
	Erratic regulator/rectifier ground.	Clean and tighten the ground terminals.
Charge unsteady	Terminal insulator worn due to vibration is causing transient short circuits.	Repair or replace.
	Short circuits inside generator.	Replace.
	Regulator/rectifier faulty.	Replace.

Electrical system troubleshooting information (Aprilia RS125/3)