Honda GCV520 Owner's Manual page 25

4. Spark plug service
Recommended spark plugs:
Never use a spark plugs of incorrect heat range.
To ensure proper engine operation, the spark plugs must be
properly gapped and free of deposits.
1. Remove the spark plug caps and use a spark plug wrench to
remove each spark plug.
If the engine has been running, the muffler will be very hot. Be
careful not to touch the muffler.
2. Visually inspect the spark plugs. Discard the spark plug if there
is apparent wear, or if the insulator is cracked or chipped. Clean
the spark plugs with a wire brush if they are to be reused.
3. Measure the plug gap with a feeler gauge. Correct as necessary
by bending the side electrode.
The gap should be:
0.70 0.80 mm (0.028 0.031 in)
BPR5ES (NGK)
W16EPR-U (DENSO)
SPARK PLUG WRENCH
0.70 0.80 mm
(0.028 0.031 in)
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