Re: stripped spark plug thread

[olcah]

As it may help someone else with the same problem, I tried the Helicoil Save a Thread insert kit on my 54 Evinrude 25 HP. The head did not tap well. The tap tore the aluminum head material without cutting clean threads. The head is quite thin so the tapped thread was short. The insert just pulled out. For 1950s big twins I recommend finding another head (which I did) or maybe welding the thread area and retapping. That’s just my 2 cents. Others clearly have had better experience, but maybe not with this engine. I surely do appreciate the advice and comments above. Thank you.