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

Trouble	Symptom and possible causes	Remedy
Difficulties on starting	Starter jet obstructed.	Clean.
	Starter duct obstructed.	Clean.
	Air leaking past the gasket between cold-start body and carburetor.	Check and tighten.
	Cold-start shutter is malfunctioning.	Repair.
Erratic operation at idling speed or in the low speed range	Idle jet obstructed or loose.	Check and clean.
	Air leaking past the S.I.P.C. tube of carburetor or cold-start device.	Check.
	Idle outlet or by-pass hole obstructed.	Check and clean.
	Cold-start shutter does not close fully.	Check and adjust.
Erratic operation in the mid-to-high speed range	Main jet obstructed.	Check and clean.
	Build-up sticking to tapered needle.	Check and clean.
	Throttle valve malfunctioning.	Check throttle valve operation.
	Filter obstructed.	Inspect and clean.
Erratic overflow and fuel level	Needle valve worn or damaged.	Replace.
	Float is malfunctioning.	Check and adjust.
	Debris build-up on needle valve.	Clean.
	Fuel level too high or too low.	Adjust float height.
	Carburetor breather hose obstructed.	Clean.
	Needle valve spring broken.	Replace.

Carburetor troubleshooting information (Aprilia RS125/3)