TESTING PROCEDURE ............................................................................................................................... 67
SERVICE ....................................................................................................................................................... 68
SPARK PLUG SERVICE ............................................................................................................................... 68
IGNITION TIMING PROCEDURE ................................................................................................................. 68
SERVICE TIPS .............................................................................................................................................. 71
GENERAL INFORMATION ............................................................................................................................ 72
OPERATION .................................................................................................................................................. 72
4-CYCLE ENGINE THEORY ......................................................................................................................... 72
LUBRICATION SYSTEMS ............................................................................................................................. 73
COUNTERBALANCE SYSTEMS .................................................................................................................. 73
COMPONENTS ............................................................................................................................................. 74
ENGINE OPERATION PROBLEMS .............................................................................................................. 75
TESTING ....................................................................................................................................................... 77
ENGINE KNOCKS ......................................................................................................................................... 77
ENGINE OVERHEATS .................................................................................................................................. 77
SURGES OR RUNS UNEVENLY .................................................................................................................. 77
ENGINE MISFIRES ....................................................................................................................................... 77
ENGINE VIBRATES EXCESSIVELY ............................................................................................................. 78
BREATHER PASSING OIL ............................................................................................................................ 78
EXCESSIVE OIL CONSUMPTION ................................................................................................................ 78
LACKS POWER ............................................................................................................................................. 78
SERVICE ....................................................................................................................................................... 79
DISASSEMBLY PROCEDURE ...................................................................................................................... 79
CYLINDERS .................................................................................................................................................. 81
CYLINDER HEADS ....................................................................................................................................... 82
CRANKSHAFTS AND CAMSHAFTS ............................................................................................................ 84
VALVES ......................................................................................................................................................... 85
CRANKCASE BREATHERS .......................................................................................................................... 86
CRANKSHAFT BEARING SERVICE ............................................................................................................. 88
COUNTERBALANCE SERVICE .................................................................................................................... 89
FLYWHEEL SERVICE ................................................................................................................................... 89
SEARS CRAFTSMAN CROSS REFERENCE SUPPLEMENT INCLUDED IN BACK OF BOOK
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