Use and Care Manual

14
SERVICE AND MAINTENANCE
Air Filter
NOTE: Not all engines have air filters, such as engines used for
snow blowers. Service the air filter if one is present.
Paper filters cannot be cleaned and must be replaced once a year
or every 100 operating hours; more often if used in extremely
dusty conditions.
WARNING
Never use gasoline or low flash point solvents for
cleaning the air cleaner element. A fire or explosion
could result.
NOTE: Never run the engines that have air filters without them.
Rapid engine wear can result.
1. Press the tab on the air filter cover and lift the cover, or un-
thread the thumbscrew, depending on the model of engine
(Figure 11).
Figure 11
2. Replace paper element when dirty or damaged. Clean foam
element or replace when damaged.
3. 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.
Adjustments
DO NOT make any engine adjustments. Factory settings are
satisfactory for most conditions. If adjustments are needed,
contact your Authorized MTD Servicing Dealer.
Spark Plug Service
WARNING
DO NOT check for spark with spark plug removed. DO NOT
crank engine with spark plug removed.
Check the spark plug yearly or every 100 operating hours. To
ensure proper engine operation, the spark plug must be properly
gapped and free of deposits.
1. Remove the spark plug boot (Figure 8).
2. Clean the area around the spark plug.
3. Use a spark plug wrench to remove the spark plug.
WARNING
If the engine has been running, the muffler, engine head
and spark plug will be very hot. Be careful not to touch
any of these components until they have cooled.
4. Visually inspect the spark plug. Discard the spark plug if there
is apparent wear, or if the insulator is cracked or chipped.
Replace the spark plug if the electrodes are pitted, burned or
fouled with deposits.
5. Clean the spark plug with a wire brush if it is to be reused.
6. Measure the plug gap with a feeler gauge. Correct as
necessary by bending side electrode (a) (Figure 10). The gap
should be set to 0.030 - .06 in. (0.76 - 1.5 mm).
7. Check that the spark plug washer is in good condition
8. Thread the spark plug in by hand to prevent cross-threading.
9. 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.
NOTE: The spark plug must be securely tightened. An
improperly tightened spark plug can become very hot and
may damage the engine.
0.03-0.06 in.
0.76-1.5 mm
a
Figure 10