15
0.6mm
(0.024 in.)
CAUTION!
Never allow dirt or debris to enter the cylinder bore! Before remov-
ing the spark plug, thoroughly clean the spark plug and cylinder head
area! Allow the engine to cool before servicing the spark plug! Cylinder
threads can be damaged by tightening or loosening the spark plug while
the engine is hot!
Clean the spark plug
and check the gap
at the electrode.
Figure 14
NGK CMR5H
Counter-
clockwise
to remove.
1. Use the spark plug wrench to remove the spark plug. See Figure 14.
2. Clean and adjust the spark plug gap
to 0.6mm (0.024 in.). If the plug must be replaced, use a NGK CMR5H
or equivalent type plug of the correct
heat range.
3. Install the spark plug finger-tight in the cylinder head, then tighten it
firmly with the spark plug wrench. If a torque wrench is available, torque
the spark plug to 16.7-18.6 Nm (148-165 inch-pounds)
Spark Plug
Cooling System
CAUTION!
The engine is cooled by air drawn into the air intake cover on the blower
housing. The blower fan then pushes the cooling air through an opening in
the fan housing, forcing it past the cylinder cooling fins. Failure to keep the
cooling system and its passages clear of debris will likely result in engine
overheating, a major cause of serious engine problems that can lead to
failure.
• Remove all dirt and debris from blower exterior and the engine. Check the
cooling fins and air cleaner for clogging and clean as necessary.
1. Remove engine cover.
2. Clean cylinder fins to allow cooling air to pass freely.
• Carefully remove any accumulations of dirt or debris from the muffler and
fuel tank. Dirt build-up in these areas can lead to engine overheating, fire
or premature wear.
