10 - 2TRBLSHTGSTARTING FAILURE/HARD STARTING/POOR IDLE SPEEDPERFORMANCE/POOR MEDIUM AND HIGH-SPEED PERFORMANCECOMPRESSION SYSTEMCylinder and cylinder head• Loose spark plug• Loose cylinder head or cylinder• Broken cylinder head gasket• Broken cylinder gasket• Worn, damaged or seized cylinderValve, camshaft and crankshaft• Improperly sealed valve• Improperly contacted valve and valve seat• Improper valve timing• Broken valve spring• Seized camshaft• Seized crankshaftPiston and piston rings• Improperly installed piston ring• Worn, fatigued or broken piston ring• Seized piston ring• Seized or damaged pistonCrankcase and crankshaft• Improperly seated crankcase• Seized crankshaftValve train• Improperly adjusted valve clearance• Improperly adjusted valve timingEBS00538POOR IDLE SPEED PERFORMANCEPOOR IDLE SPEED PERFORMANCECarburetor• Improperly returned starter plunger• Loose pilot jet• Clogged pilot jet• Clogged pilot air jet• Improperly adjusted idle speed (throttle stopscrew)• Improper throttle cable play• Flooded carburetorElectrical system• Faulty spark plug• Faulty C.D.I. unit• Faulty pickup coil• Faulty charging/rotor rotation directiondetection coil• Faulty ignition coilValve train• Improperly adjusted valve clearanceAir filter• Clogged air filter elementEBS00539POOR MEDIUM AND HIGH-SPEED PERFORMANCEPOOR MEDIUM AND HIGH-SPEED PERFORMANCERefer to “STARTING FAILURE/HARD STARTING” and “POOR IDLE SPEED PERFORMANCE—Valve train”.Carburetor• Improper jet needle clip position• Improperly adjusted fuel level• Clogged or loose main jet• Deteriorated or contaminated fuelAir filter• Clogged air filter element10www.midwestmanuals.com
