MTD 08M - Manual (Page 20)

20 s
ectiOn
10— e
ngine
M
aintenance
Electrode
0.030 in.
Figure 10-4
3. Measure the plug gap with a feeler gauge. Correct as
necessary by bending side electrode. See Fig. 10-4. The
gap should be set to 0.030 in.
4. Check that the spark plug washer is in good condition
and thread the spark plug in by hand to prevent cross-
threading.
5. After the spark plug is seated, tighten with a spark plug
wrench to compress the washer.
NOTE: When installing a new spark plug, tighten 1/2 turn
after the spark plug seats to compress the washer. When
reinstalling a used spark plug, tighten 1/8-1/4 turn after the
spark plug seats to compress the washer.
IMPORTANT: The spark plug must be securely tightened.
An improperly tightened spark plug can become very hot
and may damage the engine.
Spark Plug Service
WARNING: DO NOT check for spark with spark
plug removed. DO NOT crank engine with spark
plug removed.
To ensure proper engine operation, the spark plug must be
properly gapped and free of deposits.
Remove the spark plug boot and use a spark plug wrench 1.
to remove the plug. See Fig. 10-3.
WARNING: If the engine has been running, the
muffler will be very hot. Be careful not to touch the
muffler.
2. Visually inspect the spark plug. Discard the spark plug
if there is apparent wear, or if the insulator is cracked or
chipped. Clean the spark plug with a wire brush if it is to be
reused.
Spark Plug
Spark Plug Boot
Figure 10-3