Honda NRX1800 2004 Owner's Manual page 128

(3)
(3) spark plug gap
7. With the plug washers attached, thread
the spark plugs in by hand to prevent
cross-threading.
(4)
(4) side electrode
8. Tighten each spark plug:
1/8-1/4 turn after it seats (if the old
plug is good)
1/2 turn after it seats (if installing a
new plug)
Improperly tightened spark plugs can
damage the engine. If a plug is too loose,
a piston may be damaged. If a plug is too
tight, the threads may be damaged.
Servicing Your Honda
Spark Plugs
(cont'd)
119