Honda Outboard motor BF8D/9.9D Owner's Manual page 65

SERVICING YOUR HONDA OUTBOARD MOTOR
6.
Install the spark plugs carefully, by
hand, to avoid cross-threading.
7.
8.
9.
After each spark plug seats, tighten
with a spark plug wrench supplied in
the tool kit to compress the sealing
washer.
If reinstalling the used spark plugs,
tighten l/8 - l/4 turn after the spark
plugs seat.
If reinstalling new spark plugs,
tighten l/2 turn after the spark plugs
seat.
Loose spark plugs can over heat and
damage the engine. Overtightening
the spark plugs can damage the
threads in the cylinder head.
Attach the spark plug caps.
Install and lock the engine cover.
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