Honda 2004 XR400R, Owner'S Manual

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− − 0.024 0.028 in (0.60 0.70 mm)
85
Spark Plug
Servicing Your Honda
Improperly tightened spark plugs can damage
the engine. Too loose, you can burn a piston.
Too tight, you can damage the threads.
Disconnect the spark plug cap. Tighten the spark plug:
Remove the spark plug with the multi-
purpose wrench ( ) provided with your
motorcycle.
With the plug washer attached, thread the
spark plug in by hand (to prevent cross-
threading).
If you have to install a new plug, first check
the gap.
Make sure the plug washer is in good
condition.
Check the spark plug gap ( ), using a wire-
type feeler gauge. If adjustment is necessary,
bend the side electrode carefully. The gap
should be:
Inspect the spark plug electrodes for wear.
The center electrode ( ) should have square
edges. The side electrode ( ) should not be
eroded. The insulator should not be cracked
or chipped.
about 1/8-1/4 turn after it seats (if the old
plug is good).
about 1/2 turn after it seats (if installing a
new plug).
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03/05/20 10:09:18 31KCY680_094