MTD 179cc - Spark Plug Service and Engine Cleaning

11
Spark Plug Service
WARNING: DO NOT check for spark
with spark plug removed. DO NOT
crank engine with spark plug removed.
WARNING: If the engine has been run-
ning, the muffler will be very hot. Be
careful not to touch the muffler.
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1.
wrenchtoremovetheplug,Figure3-2.
Visuallyinspectthesparkplug.Discardthespark2.
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.
Measure the plug gap with a feeler gauge. Correct 3.
asnecessarybybendingsideelectrode,Figure
3-3. The gap should be set to 0.02-0.03 inches
(0.60-0.80mm).
Checkthatthesparkplugwasherisingoodcondi-4.
tionandthreadthesparkpluginbyhandtoprevent
cross-threading.
Afterthesparkplugisseated,tightenwithaspark5.
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 tightened
securely. An loose spark plug can become very hot
and can damage the engine.
Cleaning the Engine
If the engine has been running, allow it to cool for at least
half an hour before cleaning. Periodically remove dirt
build-up from engine.
IMPORTANT: Do not spray engine with water to
clean because water could contaminate fuel. Using
a garden hose or pressure washing equipment can
also force water into the muffler opening. Water that
passes through the muffler can enter the cylinder,
causing damage.
WARNING: Accumulation of debris
around muffler could cause a fire.
Inspect and clean before every use.
3
Maintaining
the
Engine
WARNING
DO NOT check for spark
with spark plug removed.
DO NOT crank engine
with spark plug removed.
If the engine has been
running, the muffler will
be very hot. Be careful
not to touch the muffler.
Figure3-2:Thesparkplugandboot.
Figure3-3:Useafeelergaugetomeasurethepluggap.
SparkPlug
SparkPlugBoot
0.02-0.03 in.
0.60-0.80mm
Electrode