Honda TRX400X 2009 Owner's Manual page 122

Spark Plug
4. Inspect the electrode and center porcelain for deposits, corrosion, or
carbon fouling. If the corrosion or deposits are heavy, replace the
plug. Clean a carbon or wet-fouled plug with a plug cleaner, if
available, or a wire brush. Inspect the spark plug electrodes for wear.
The center electrode ( ) should have a flat tip and sharp edges, and
the side electrode ( ) should not be eroded. If the electrodes and
insulator tip appear unusually fouled or burned, we suggest that you
contact your Honda dealer.
5. Discard the spark plug if there is apparent wear or if the insulator is
cracked or chipped.
6. Using a wire-type feeler gauge, check the spark plug gap ( ). If
adjustment is necessary, bend the side electrode carefully.
The gap should be:
0.024 0.028 in (0.60 0.70 mm) −
(2) center electrode
(3) side electrode
Servicing Your Honda
114
2
3
−
(3)
(2)
(4)
0.024 0.028 in −
(0.60 0.70 mm) −
(4) spark plug gap
4