MAINTENANCE
Refer to Recommended Maintenance Schedule in Fig. 14 for maintaining the spark plug.
The spark plug is important for proper engine operation. Check the spark plug regularly to maintain proper
engine operation. A good spark plug should be intact, free of deposits, and properly gapped.
SPARK PLUG MAINTENANCE
To inspect or replace the spark plug:
1. Pull on the spark plug boot to remove it (Fig. 20). Be careful
not to tear insulation or wire.
2. Remove the spark plug rubber boot and unscrew the spark plug
from the engine using the spark plug wrench provided (Fig. 21).
TIP:
There is limited space for the wrench to turn. Use both rows
of holes in the spark plug wrench to gain leverage to loosen the
plug.
3. Visually inspect the spark plug. If it is cracked or chipped, or if
the electrodes are worn or burned, discard it and replace with a
new spark plug.
We recommend replacing with an
NGK BP7ES/Torch F7TC
spark
plug
(part no. DF475-145), available for purchase at
wenproducts.com
.
4. If re-using the spark plug, use a wire brush to clean any dirt
from around the spark plug base, then re-gap the spark plug.
5. Measure the plug gap with a spark plug gap gauge. The gap
should be 0.7 to 0.8 mm (0.028-0.031 in.) (Fig. 22). Carefully ad-
just the gap if necessary.
6. Screw the spark plug back into the spark plug hole using the
spark plug wrench. Do not over-tighten spark plug. Recommended
tightening of spark plug is
½ to ¾ of a turn
(15 ft-lb torque/20.33
Nm) after spark plug gasket contacts spark plug hole.
7. Reinstall the spark plug boot over the spark plug.
Fig. 20
Plug Wrench
Spark Plug Boot
Spark Plug
Boot
Cylinder
Assembly
Fig. 21
Fig. 22
29
0.7 - 0.8 mm