xvi Engine Diagnosis . . . . . . . . . . . . . . . 468 Normal Wear . . . . . . . . . . . . . . . . . . . .470 Lubrication Failure . . . . . . . . . . . . . . . .471 Foreign Material Damage . . . . . . . . . . .471 Overheating . . . . . . . . . . . . . . . . . . . . .471 Detonation and Preignition . . . . . . . . . .472 Engine Reassembly . . . . . . . . . . . . . 473 Crank Seal Installation . . . . . . . . . . . . .473 Oil and Grease Types . . . . . . . . . . . . . . 474 Checking for Binding after Each Installation . . . . . . . . . . . . . . . . . . . . 474 Sealants. . . . . . . . . . . . . . . . . . . . . . . . 474 Rotary Valve Timing . . . . . . . . . . . . . . . 474 Top End Reassembly . . . . . . . . . . . . 474 Torque Sequence . . . . . . . . . . . . . . . . .475 Crankcase Pressure Test . . . . . . . . . . . .475 Ignition Timing . . . . . . . . . . . . . . . . . . . 476 Engine Reassembly Summary. . . . 476 Installing the Engine in the Frame . . . . . . . . . . . . . . . . . . 477 Initial Engine Start-Up and Operation . . . . . . . . . . . . . . . . . . . . 477 Chapter 22 Four-Stroke Engine Overhaul. . . . . . . 481 Engine Top End Service . . . . . . . . . 481 Cleaning and Decarbonizing . . . . . . . . .481 Top End Inspection and Measurement . . . . . . . . . . . . . . . . . .482 Reconditioning the Cylinder Head Assembly . . . . . . . . . . . . . . . . . . . . .486 Piston and Cylinder Inspection and Service . . . . . . . . . . . . . . . . . . .490 Engine Bottom End Service. . . . . . 492 Inspection and Measurement of Bearings. . . . . . . . . . . . . . . . . . . .493 Checking Oil Pump Condition . . . . . . . .493 Cleaning Oil Passages and Bottom End Filters. . . . . . . . . . . . . . . . . . . . .494 Diagnosis of Oil System Problems . . . . .494 Engine Balancer Inspection. . . . . . . . . .495 Crankshaft Measurement and Reconditioning . . . . . . . . . . . . . . . . .495 Connecting Rod Reconditioning (Plain Bearing) . . . . . . . . . . . . . . . . .496 Engine Measurement and Inspection Summary . . . . . . . . . . 496 General Inspection . . . . . . . . . . . . . . . .497 Top End Components . . . . . . . . . . . . . .497 Bottom End Components . . . . . . . . . . .497 Oil Pump . . . . . . . . . . . . . . . . . . . . . . .498 Four-Stroke Engine Reassembly . . . . . . . . . . . . . . . . . . . 498 Plain Bearing Installation . . . . . . . . . . .498 Crankshaft and Transmission Shaft Installation . . . . . . . . . . . . . . . . . . . .498 Oil and Grease Use. . . . . . . . . . . . . . . .499 Sealing Compounds . . . . . . . . . . . . . . .499 Timing of Engine Balancers. . . . . . . . . .499 Torque Pattern and Final Torque Value . . .499 Piston Ring Installation . . . . . . . . . . . . .500 Piston Installation . . . . . . . . . . . . . . . . .500 Cylinder Installation . . . . . . . . . . . . . . .500 Cam Timing . . . . . . . . . . . . . . . . . . . . .501 Four-Stroke Engine Reassembly Summary . . . . . . . . . . . . . . . . . . . . .501 Engine Installation . . . . . . . . . . . . . . . .504 Initial Engine Running . . . . . . . . . . . . . .504 Engine Break-In Procedures . . . . . . . . .505 Post-Overhaul Checkup. . . . . . . . . . . . .505