Spark Plug Service - Honda HP400 Owner's Manual

Spark Plug Service
Recommended spark plug: BPR4ES (NGK)
W14EPR-U (DENSO)
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To ensure proper engine operation, the spark plug must be properly gapped
and free of deposits. If the engine has been running, the muffler will be very
hot. Be careful not to touch the muffler.
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1. Remove the spark plug cap.
2. Clean any dir-l from around the spark plug base.
3. Use the wrench supplied in the tool kit to remove the spark plug.
4. Inspect the spark plug. Discard it if the electrodes are worn or if the insulator
is cracked or chipped. If it is to be reused, clean the electrode and insulator
with a wire brush.
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