Cleaning And Adjusting Spark Plug - Yamaha F300A Owner's Manual

Maintenance
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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
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.
1. Remove the flywheel cover from the rear
side.
2. Remove the bolts to remove the rear
cover.
3. Remove the bolts to remove the covers
of both port and starboard sides.
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4. Remove the bolts to move the plate.
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5. Remove the bolts that are securing the
ignition coil, and then remove the igni-
tion coil. Do not use any tools to remove
or install the ignition coil, otherwise the
ignition coil coupler may get damaged.
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