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TROUBLESHOOTING
SERVICE MANUAL NUMBER 23
Page 1C-7
90-861326--1 MARCH 1999
Splashed Deposits
Spotted deposits, which sometimes occur after long delayed tune-up, accumulate after a
long period of misfiring. When normal combustion temperatures are restored, upon
installation of new plugs, deposits loosen from top of piston and head and are thrown against
hot insulator. Plugs can be serviced (clean, file and re-gap) and reinstalled.
72423
Mechanical Damage
Mechanical damage to spark plug firing end is caused by foreign object in combustion
chamber. Because of valve overlap, small objects can travel from one cylinder to another.
Check all cylinders, intake manifold and exhaust material to prevent further damage.
Replace spark plugs.
72423
IMPORTANT: When working on engine, spark plug holes and carburetor throat
should be kept covered to prevent foreign objects from entering combustion
chamber.
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