Re: mercury spark plug torque setting
That means any tighter than 20 ft/lbs and pull the head(s), drill out the spark plug hole(s), tap the hole(s), insert a helicoil (thread repair insert) and reinstall the heads because you overtightened the spark plugs and destroyed the threads in the aluminum cylinder heads. Turn a $12 spark plug change into a $100 repair very quickly.<br /><br />Don't ask me how I know this.....
