APRILIA RS 250, Service And Repair Manual

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8 - 7 M SERVICING INFORMATION
Complaint Symptom and possible causes Remedy
Engine will not start, Compression too low
or is hard to start 1. Excessively worn cylinder or piston rings. Replace.
2. Stiff piston ring in place. Repair or replace.
3. Gas leaks from the joint in crankcase, cylinder or
cylinder head. Repair or replace.
4. Spark plug too loose. Tighten.
5. Broken, cracked or otherwise failed piston. Replace.
6. Worn crankshaft oil seal. Replace.
Plug not sparking
1. Fouled spark plug.
Replace.
2. Wet spark plug. Clean and dry.
3. Defective ignition coil. Replace.
4. Open or short in high-tension cord. Replace.
5. Defective ignition system. Repair or replace.
No fuel reaching the carburettor
1. Clogged air vent hole in the fuel tank cap.
Clean.
2. Clogged or defective fuel cock. Clean or replace.
3. Defective carburettor needle valve. Replace.
4. Clogged fuel pipe. Clean.
Engine stalls 1. Fouled spark plug. Clean.
easily 2. Defective ignition system. Repair or replace.
3. Clogged fuel pipe. Replace.
4. Clogged jets in carburettor. Clean.
Noisy engine Noise appears to come from piston
1. Piston or cylinder worn down.
Replace.
2. Combustion chamber fouled with carbon. Clean.
3. Piston pin or piston pin bore worn. Replace.
4. Piston ring groove worn. Replace.
5. Piston pin bearing worn. Replace.
Noise seems to come from clutch
1. Worn splines of countershaft or hub.
Replace.
2. Worn teeth of clutch plates. Replace.
3. Distorted clutch plates, driven and drive. Replace.
Noise seems to come from crankshaft
1. Rattling bearings due to wear.
Replace.
2. Big-end bearings worn and burnt. Replace.
3. Crankshaft bearing worn and burnt. Replace.
Noise seems to come from transmission
1. Gears worn or rubbing.
Replace.
2. Badly worn splines. Replace.
3. Primary gears worn or rubbing. Replace.
TROUBLESHOOTING
ENGINE