Servicing The Spark Plug - Hayter Harrier 41 PRO AD FS Operator's Manual

MAINTENANCE

Servicing the Spark Plug

Improper maintenance, use of nonconforming
replacement components, or the modifi cation of the
spark plug may cause death or serious injury.
Recommended Spark Plug: BPR5ES (NGK)
The recommended spark plug has the correct heat
range for normal engine operating temperatures.
IMPORTANT: An incorrect spark plug can cause
engine damage.
If the engine has been running, let it cool before
servicing the spark plug.
For good performance, the spark plug must be
properly gapped and free of deposits.
1. Disconnect the spark plug cap, and remove any dirt
from around the spark plug area.
2. Remove the spark plug with the spark plug wrench
(1).
(Refer to fi g.29)
3. Visually inspect the spark plug. Discard the spark
Fig. 29
0.7–0.8 mm
(0.028-0.031 in) 2
1
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.
4. Measure the spark plug gap with a feeler gauge
(2). Correct as necessary by bending the side
electrode.
The gap should be: 0.028 - 0.031 in (0.7 - 0.8 mm)
(Refer to fi g.29)
5. Check that the spark plug washer is in good
condition and thread the spark plug by hand to
prevent cross-threading (3).
(Refer to fi g.29)
6. After the spark plug is seated, tighten with the
spark plug wrench to compress the washer.
When installing a new spark plug, tighten 1/8 - 1/4 turn
after the spark plug seats to compress the washer.
Torque to: 20 Nm (15 lbf-ft 2.0 kgf.m)
IMPORTANT: A loose spark plug can over heat and
damage the engine. Over tightening the spark plug
can damage the threads in the cylinder head.
7. Attach the spark plug cap to the spark plug (1).
(Refer to fi g.30)
Fig. 30
3
1
20