Honda Supra GTR150 2020 Owner's Manual page 59

Spark plug gap
11. Make sure the plug washer is in good
condition.
12. Install the spark plug. With the plug
washer attached, thread the spark plug in
by hand to prevent cross-threading.
13. Tighten the spark plug:
Side electrode
Plug washer
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.
14. Install the parts in the reverse order of
Spark Plug
u
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
removal.
When reinstalling the spark plug cap,
u
take care to avoid pinching any cable
or wires.
Checking Spark Plug
55