Honda EB3500X Owner's Manual page 27

Spark plug service
Recommended spark plug: BPR5ES (NGK) WlGEPR-U (ND)
CAUTION: Never use a spark plug of incorrect heat range.
To ensure proper engine operation, the spark plug must be properly gapped
and free of deposits.
1. Remove the spark plug cap, and use a spark plug wrench to remove the
plug.
mm!
If the engine has been running, the muffler will be very hot. Be
careful not to touch the muffler.
2. Visually inspect the spark plug. Discard it 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. The gap should be 0.7-0.8
mm (0.028-0.031 in).
0.7-0.8 mm
~0.028-0.031 in)
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