Product Manual

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 adjust 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 tighten-

ing 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. 19

Plug Wrench

Spark Plug Boot

Spark

Plug

Boot

Cylinder

Assembly

Fig. 20

Fig. 21

0.7 - 0.8 mm