Spark Plug Service - MTD 240 Series Operator's Manual

Remove the thumb screw and the air cleaner cover.
Remove the elements and separate them. See Fig. 10-2.
Replace paper element when dirty or damaged. Clean
foam element or replace when damaged.
Paper Element
Foam Element
Figure 10=2
2. To clean foam element, separate it from the paper element
and wash in liquid detergent and water. Allow to dry
thoroughly before using. Do not oil the foam element.
SparkPlugService
_ 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.
1. Remove the spark plug boot and use a spark plug wrench
to remove the plug. See Fig. 10-3.
Spark Plug
Spark Plug
Figure 10=3
_ ARNING: 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.
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.
Electrode
_ 0.030 in.
4_
5_
Figure 10-4
Check that the spark plug washer is in good condition
and thread the spark plug in by hand to prevent cross-
threading.
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.
SECTION 10--
ENGINE MAINTENANCE