Honda Power Products UMC425E Manuel De L'utilisateur page 50

3.Spark plug service
Recommended spark plug: CMR5H (NGK)
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.
CAUTION:
Never use a spark plug of incorrect heat range.
1.Loosen the 5 mm hex socket bolt with a hexagon wrench, then
remove the top cover.
2.Remove the spark plug cap and use the proper size spark plug
wrench to remove the spark plug.
3.Visually inspect the spark plug. Discard it if there is apparent wear or
the insulator is cracked or chipped. Clean the spark plug with a wire
brush if it is to be reused.
5mm SOCKET BOLT
TOP COVER
SPARK PLUG WRENCH
SPARK PLUG
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