Honda HSM1380i Owner's Manual page 91

4. Measure the plug gap with a feeler gauge.
Correct as necessary by carefully bending the side electrode.
The gap should be:
0.7 0.8 mm (0.028 0.031 in) −
Recommended spark plug: BPR5ES (NGK)
SIDE ELECTRODE
SEALING WASHER
5. Make sure that the sealing washer is in good condition and thread
the spark plug in by hand to prevent cross-threading.
6. After the spark plug is seated, tighten with a spark plug wrench to
compress the washer.
If installing a new spark plug, tighten 1/2 turn after the spark plug seats
to compress the washer. If reinstalling a used spark plug, tighten 1/8 to
1/4 turn after the spark plug seats.
7. Install the spark plug cap securely.
Use only the recommended spark plug or equivalent. Spark plug
which has an improper heat range may cause engine damage.
The spark plug must be securely tightened. An improperly
tightened spark plug can become very hot and may damage the
engine.
88
−
W16EPR-U (DENSO)
0.7 0.8 mm −
(0.028 0.031 in) −