Honda HP500H Manuel De L'utilisateur page 41

Spark plug service
Recommended spark plug: BPR6ES (NGK)
If the engine has been running, the muffler will be very hot. Be careful
not to touch the muffler.
To ensure proper engine operation, the spark plug must be properly
gapped and free of deposits.
1.Clean any dirt from around the spark plug base.
2.Disconnect the spark plug cap and then remove the spark plug with
the spark plug wrench.
3.Visually inspect the spark plug. Discard it 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 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)
PLUG WRENCH
CAUTION:
• The spark plug must be securely tightened. An improperly tightened
spark plug can become very hot and may damage the engine.
• Use only the recommended spark plug or equivalent. Spark plugs
which have an improper heat range may cause engine damage.
38
W20EPR-U (DENSO)
SIDE
ELECTRODE
PLUG GAP:
0.7–0.8 mm
(0.028–0.031 in)