Honda VTX1300C VTX 2004 Owner's Manual page 117

Spark Plugs
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.
9. Reinstall the spark plug caps. Take care
to avoid pinching any cables or wires.
10. Reinstall the over head covers (page
106 ).
108
Servicing Your Honda