G
RASS
T
RIMMER
O
PERATOR
'
S
M
ANUAL
19
SPARK
PLUG
Level 2.
Tools Required: Spark Plug socket wrench and screw driver, Feeler
gauge. Preferably a wire gauge.
Parts Required: Spark Plug, NGK BPM-8Y P/N 15901019830
1.
Remove 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.).
COOLING
SYSTEMS
CLEANING
Level 2.
Tools required:
Cross Head Screwdriver, 3 mm Hex Wrench, Cleaning
Brush, 25-50 mm (1-2 in.) medium bristle paint brush.
Parts Required: None.
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.
0.65 mm
(0.026 in.)
