Honda Power Products WB20XT Guide De L'utilisateur page 27

3. Spark plug service
Recommended spark plug: BPR6ES(NGK)
To ensure proper engine operation, the spark plug must be properly
gapped and free of deposits.
1. Disconnect the spark plug cap and then remove the spark plug with
the spark plug wrench.
If the engine has been running, the muffler will be very hot. Be careful
not to touch the muffler.
SPARK PLUG CAP
2. Visually inspect the spark plug. Discard the spark plug 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.
3. Measure the plug gap with a feeler gauge.
Correct as necessary by bending the side electrode.
The gap should be:
0.7—0.8 mm (0.028—0.031 in)
24
0.7—0.8 mm
(0.028—0.031 in)