The 2001-2005 Yamaha FZ1 repair manual by Clymer, covers the following models:
Yamaha FZ1, 2001-2005
Yamaha FZS1000, U.K. 2001-2003
Book Excerpt: 2001-2005 Yamaha FZ1 Repair Manual
Unusual noises are often the first indication of a developing problem. Investigate any new noises as soon as possible. Something that may be a minor problem, if corrected, could prevent the possibility of more extensive damage.
Use a special mechanic's stethoscope or a small section of hose held near the ear (not directly on the ear) with the other end close to the source of the noise to isolate the location.
Determining the exact cause of a noise can be difficult. If this is the case, consult with a professional mechanic to determine the cause. Do not disassemble major components until all other possibilities have been eliminated.
Consider the following when troubleshooting engine noises:
A knocking or pinging during acceleration may be caused by using a lower octane fuel than recommended. May also be caused by poor fuel.
Pinging can also be caused by an incorrect spark plug heat range or carbon buildup in the combustion chamber. Refer to the Spark Plug Heat Range and Compression Test in Chapter Three.
A slapping or rattling noises at low speed or during acceleration may be caused by excessive piston-to-cylinder wall clearance (piston slap).
NOTE: Piston slap is easier to detect when the engine is cold and before the pistons have expanded. Once the engine has warmed up, piston expansion reduces piston-to-cylinder clearance.
A knocking or rapping while decelerating is usually caused by excessive rod bearing clearance.
A persistent knocking and vibration occurring every crankshaft rotation is usually caused by worn rod or main bearing(s). Can also be caused by broken piston rings or damaged piston pins.
A rapid on-off squeal indicates a compression leak around cylinder head gasket or spark plug(s).
Excessive valve train noise may indicate the following:
Excessive valve clearance.
Worn or damaged camshaft.
Damaged camshaft, camshaft drive chain and guides.