Spark Plug Service - MTD 679 cc Manual Del Operador

Figure 6-7
8. Attach the air filter cover. See Figure 6-8.
Turn thumb screws clockwise a 1/4 turn
until snug. Check for any misalignment.
2
Air Filter
Cover
Figure 6-8
10 S 6 — M
ection aintenance

Spark Plug Service

To ensure proper engine operation, the spark
plug must be properly gapped and free of
deposits.
1. Remove the spark plug boot and use a
spark plug wrench to remove the plug.
See Figure 6-9.
Intake
Manifold
Spark Plug
Boot
1
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.
3. Measure the plug gap with a feeler
gauge. Correct as necessary by bending
electrode. See Figure 6-10. The gap
should be set to 0.024-0.031 in.
WARNING: DO NOT check for
spark with spark plug removed.
DO NOT crank engine with spark
plug removed.
WARNING: If the engine has
been running, the muffler will be
very hot. Be careful not to touch
the muffler.
Figure 6-9
Electrode
0.024-0.031 in.
Figure 6-10
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.
6. Repeat STEPS 1-5 to service the
remaining spark plug.