Last month I posted an email to the list regarding the aluminum plug on
top of the head on a TR3. My original plug was about 1/8 thick (down from
the original 1/2 thick plug). Bob Schaller's book "More BS About Triumphs"
recommended checking it. I got an aluminum repro plug from MOSS, but it fit
loosely after I ran a 1" 12 TPI tap through the hole. A 3/4" pipe plug
wouldn't thread in.
Turns out that a 3/4" pipe tap will thread into the hole pretty easily.
I think that it is 11-1/2 TPI. I ran the tap in and cut new pipe threads
easily and will fit a brass pipe tap from the local hardware store.
Don't take chances next time you re-do your head. Take out the original
cathodically reacted plug and replace it with a brass pipe plug instead.
I wish that I had just done this in the first place instead of all the
screwing around I did.
Bill Brewer
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