19
P
OWER
B
LOWER
O
PERATOR
'
S
M
ANUAL
SPARK
PLUG
Level 2.
Tools required: 3/4" Spark Plug deep socket, Feeler gauge (preferably
a wire gauge),
Parts Required: Spark Plug, NGK BPM-7Y, P/N 99944500071
1.
Remove spark plug (LN models; spark plug cover and spark
plug), and check for fouling, worn and rounded center electrode.
2.
Clean the plug or replace with a new one. DO NOT sand blast to
clean. Remaining sand will damage engine.
3.
Adjust spark plug gap by bending outer electrode.
4.
Tighten spark plug to 145-155 kg/cm (125-135 in. lb.).
5.
Install spark plug cover (LN models).
IMPORTANT
Always reinstall spark plug cover on LN models, otherwise engine
cooling is greatly reduced, and will cause engine failure.
COOLING
SYSTEMS
CLEANING
Level 3.
Tools required: 25mm-50mm (1in.-2in.) medium bristle paint brush,
Cross Head Screwdriver, Pointed Wood Stick.
Parts Required: None, if you are careful.
IMPORTANT
To maintain proper engine operating temperatures, cooling air must
pass freely through the cylinder fin area. This flow of air carries
combustion heat away from the engine.
Overheating and engine seizure can occur when:
• Air intakes are blocked, preventing cooling air from reaching the
cylinder.
• Dust and grass build up on the outside of the cylinder. This build up
insulates the engine and prevents the heat from leaving.
Removal of cooling passage blockages or cleaning of cooling fins is
considered “Normal Maintenance”. Any failure attributed to lack of
maintenance is not warranted.
Cleaning Grill
1.
Remove accumulated debris from intake grill between backpack
frame and blower housing.
INTAKE
GRILL
0.65 mm
(0.026 in.)
