Honda TRX420TM Owner's Manual page 145

3. Clean any dirt from around the spark plug base.
4. Disconnect the spark plug cap ( ). Take care to avoid damaging the
spark plug wire when disconnecting the cap.
5. Using a spark plug wrench provided in the tool kit, remove the spark
plug.
6. Inspect the electrodes and centre 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 centre 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.
7. Discard the spark plug if there is apparent wear or if the insulator is
cracked or chipped.
8. Using a wire-type feeler gauge, check the spark plug gap ( ). If
adjustment is necessary, bend the side electrode carefully.
The gap should be:
1.00 1.10 mm (0.039 0.043 in)
LEFT SIDE
(3)
(3) spark plug cap
(4) centre electrode
3
4
5
Spark Plug
1.00 1.10 mm
(0.039 0.043 in)
(6)
(5) side electrode
(6) spark plug gap
Servicing Your Honda
6
(5)
(4)
(cont'd)
135