Honda BF75D Owner's Manual page 89

8. Install the spark plugs carefully, by
hand, to avoid cross-threading.
9. After each spark plug seats, tighten
with the spark plug wrench to
compress the sealing washer.
If reinstalling used spark plugs,
tighten 1/8 - 1/4 turn after the spark
plugs seat.
If installing new spark plugs,
tighten 1/2 turn after the spark
plugs seat.
Loose spark plugs can overheat
and damage the engine.
Overtightening the spark plugs can
damage the threads in the cylinder
head.
10. Install the ignition coil. Reinstall
the 6 25 mm flange bolt.
11. Push the wire connector onto the
ignition coil. Make sure it locks in
place.
12. Repeat this procedure for the
other three spark plugs.
13. Reinstall the covers.
<Optional Parts: Iridium Spark
Plug>
RECOMMENDED SPARK PLUG:
IZFR6K-11E (NGK)

Incorrect spark plugs can cause
engine damage.
Installation and removal procedure of
the iridium spark plugs are the same
as the standard spark plugs.
SERVICING YOUR OUTBOARD MOTOR
These spark plugs have an iridium
coated center electrode. 
Be sure to observe the following
when servicing iridium spark plugs.
• Do not clean the spark plugs. If an
• Use only a ''wire-type feeler
• Do not adjust the spark plug gap. If
electrode is contaminated with
accumulated objects or dirt, replace
the spark plug with a new one.
gauge'' to check the spark plug gap
if necessary. To prevent damaging
the iridium coating of the center
electrode, never use a ''leaf-type
feeler gauge.''
The gap should be 0.039 – 0.051
inches (1.0 – 1.3 mm).
the gap is out of specification,
replace the spark plug with a new
one.
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