domes spin while changing spark plugs

[puppi350]

does anyone have the domes spin on their ADA head when changing the plugs. any techniques to avoid this and cause premature o-ring wear/failure ?

[Brooks]

If the dome spins, then the tolerances are off and either the dome and/or the head shell is worn. How old are the head and domes? What size of dome and what octane fuel are you using?

The dome and the head shell have exact tolerances that prevent the dome from spinning when the head shell is torqued down. If there was a pin to prevent the dome from spinning, there would still be oring failure if the tolerances were off and the dome and/or head shell was worn. Pinning the dome does no good other than allowing you to tighten or loosen the spark plug on a part that is worn out and needs to be replaced.