2004-2005 660 Yamaha Rhino Factory Service Manual, Page 412Get this manual
STARTING FAILUREHARD STARTINGPOOR IDLE SPEED PERFORMANCEPOOR MEDIUM AND HIGH-SPEED PERFORMANCE COMPRESSION SYSTEM Cylinder and cylinder head Loose spark plug Loose cylinder head or cylinder Broken cylinder head gasket Broken cylinder gasket Worn, damaged or seized cylinder Valve, camshaft and crankshaft Improperly sealed valve Improperly contacted valve and valve seat Improper valve timing Broken valve spring Seized camshaft Seized crankshaft EBS00538
TRBL SHTG
Piston and piston rings Improperly installed piston ring Worn, fatigued or broken piston ring Seized piston ring Seized or damaged piston Crankcase and crankshaft Improperly seated crankcase Seized crankshaft Valve train Improperly adjusted valve clearance Improperly adjusted valve timing
POOR IDLE SPEED PERFORMANCE
POOR IDLE SPEED PERFORMANCE Carburetor Improperly returned starter plunger Loose pilot jet Clogged pilot jet Clogged pilot air jet Improperly adjusted idle speed (throttle stop screw) Improper throttle cable play Flooded carburetor Electrical system Faulty spark plug Faulty C.D.Iunit Faulty pickup coil Faulty chargingrotor rotation direction detection coil Faulty ignition coil Valve train Improperly adjusted valve clearance Air filter Clogged air filter element