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SPARK PLUG
Maintenance Interval
• The spark plug should be removed from the engine and checked after each 25 hours of
operation.
• Replace the spark plug after every 100 hours of operation.
CYLINDER COOLING FINS
Maintenance Interval
• The cylinder cooling fins should be cleaned after every 25 hours of operation, or once a week,
whichever comes first.
• Air must flow freely around and through the cyl-
inder cooling fins to prevent engine overheating.
Leaves, grass, dirt and debris buildup on the
fins will increase the operating temperature of
the engine, which can reduce engine perfor-
mance and shorten engine life.
Spark Plug Maintenance
1. With the engine at ambient (room) tempera-
ture, twist the high tension lead boot on the
spark plug back and forth a couple of times to
loosen the boot, then pull the boot off of the
spark plug.
2. Remove the spark plug.
3. Clean the electrodes with a stiff brush.
4. Adjust the electrode air gap to 0.6- 0.7 mm
(.024-.028 in).
5. Replace the spark plug if it is oil-fouled, damaged, or if the electrodes are worn down.
6. Do not overtighten the spark plug when installing. The tightening torque is 10.7-16.6 N·m
(95-148 in. lbs).
Cooling Fin Cleaning
1. With the engine at ambient (room) tempera-
ture, loosen the knob and remove the air clean-
er cover.
2. Twist the high tension lead boot on the spark
plug back and forth a couple of times to loosen
the boot, then pull the boot off of the spark plug.
3. Remove the four screws retaining the topcover,
then remove the topcover.
4. Clean all dirt and debris from the cooling fins
and from around the cylinder base.
5. Reinstall the topcover and the cleaner cover.
0.6 - 0.7 mm (0.024 - 0.028 inches)
TIPS
Air Cleaner Cover
Topcover
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Driver
3mm Allen Wrench
Knob