Honda MSX125SF 2017 Owner's Manual page 55

Spark Plug u Checking Spark Plug
5. Check the spark plug gap using a wire-
type feeler gauge.
u If adjustment is necessary, bend the
side electrode carefully.
The gap should be:
0.80 to 0.90 mm (0.031 to 0.035 in)
Spark plug gap
6. Make sure the plug washer is in good
condition.
7. Install the spark plug. With the plug
washer attached, thread the spark plug in
by hand to prevent cross-threading.
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8. Tighten the spark plug:
Side electrode
Plug washer
9. Reinstall the spark plug cap. Take care to
●
If the old plug is good:
1/8 turn after it seats
●
If installing a new plug, tighten it twice
to prevent loosening:
a) First, tighten the plug:
NGK: 1/2 turn after it seats.
DENSO: 3/4 turn after it seats.
b) Then loosen the plug.
c) Next, tighten the plug again:
1/8 turn after it seats.
NOTICE
An improperly tightened spark plug can damage the
engine. If a plug is too loose, a piston may be damaged.
If a plug is too tight, the threads may be damaged.
avoid pinching any cables or wires.