Honda Car Engine G100 Owner's Manual page 19

Install the spark plug carefully, by hand, to avoid cross-threading.
After the spark plug is seated, tighten with the proper size spark
plug wrench to compress the washer.
When installing a new spark plug, tighten
1/2
turn after the spark
plug seats to compress the washer.
When reinstalling the original spark plug, tighten
118
-
114
turn after
the spark plug seats to compress the washer.
I
NOTICE
I
A loose spark plug can become very hot and can damage the engine.
Overtightening the spark plug can damage the threads in the cylinder
head.
9. Attach the spark plug cap to the spark plug.