Greasing; Cleaning And Adjusting Spark Plug - Yamaha F4A Owner's Manual

Maintenance
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Greasing

Yamaha grease A (water resistant grease)
Yamaha grease D (corrosion resistant grease; for propeller shaft)
F4A
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Cleaning and adjusting spark plug

The spark plug is an important engine com-
ponent and is easy to inspect. The condition
of the spark plug can indicate something
about the condition of the engine. For exam-
ple, if the center electrode porcelain is very
white, this could indicate an intake air leak or
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carburetion problem in that cylinder. Do not
attempt to diagnose any problems yourself.
Instead, take the outboard motor to a
Yamaha dealer. You should periodically re-
move and inspect the spark plug because
heat and deposits will cause the spark plug
to slowly break down and erode. If electrode
erosion becomes excessive, or if carbon and
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