Maintanance
Cleaning and adjusting spark plug
WARNING
When removing or installing a spark plug, be careful not to damage the insulator. A damaged
insulator could allow external sparks, which could lead to explosion or fire.
The spark plug is an important engine component and is easy to inspect. The condition of the
spark plug can indicate something about the condition of the engine. For example, 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 HIDEA dealer. You should periodically remove 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 other deposits are excessive, you should replace the spark plug with
another of the correct type.
Before fitting the spark plug, measure the electrode gap with a wire thickness gauge; adjust the
gap to specification if necessary.
1. Spark plug gap
2. Spark plug I.D. mark (NGK)
When fitting the plug, always clean the gasket surface and use a new gasket. Wipe off any dirt
from the threads and screw in the spark plug to the correct torque.
NOTE
If a torque-wrench is not available when you are fitting a spark plug, a good estimate of the
cerrect torque is 1/4 to 1/2 a turn past fingertight. Have the spark plug adjusted to the correct
torque as soon as possible with a torque wrench.
Spark plug gap:
0.9-1.0mm (0.035-0.039 in)
Spark plug torque:
25.0 Nm (18.4ft-lb)(2.55kgf-m)
Standard spark plug:
BR6HS-10
33
