59 fuel tap threads

[JDC22]

Well..wouldn't you know it...I have my 59 flh almost back together and, lo and behold, after getting the tanks back from the painter he mentions that that the left tanks bottom fuel threads are pretty crappy. Like an idiot I never checked them when I purchased the tanks on e-bay (a lesson here?) as I was excited to find the correct HD hand shift tank and did not check the threads carefully. Now the tanks are back painted real purdy, and I can't seem to straighten the threads out to accept the rod threads. I tried running an old 3/4-18 tap through them, but it didn't seem to help at all-still no purchase. I'm wondering if using a brand new tap might help as the one I borrowed from my neighbor is a bit worn- would a new tap help cut deeper threads, or am I just spinning my wheels? I know this is a fairly common problem with these tanks and rods- does anybody have a suggestion or fix for me? I'd love not to ruin the paint and have to do that all over (especially when I used up every last drop of skyline blue I bought painting the bike with a spare set of foot shift tanks) as I'd end up having to buy a whole new can of paint for just the single tank...but I gotta do what I gotta do. I guessit's murphy's law, as everything was going together so well and I was a gas tank and some fluids away from taking it off the lift and firing it up.

Any advice or help would be much appreciated!

Thanks
Joel

[partshunt]

Hey joel:-
I had the same problem, only someone ruined the bung totally by retapping with a pipe tap and didnt use the original fuel shut off. My tanks are not repainted yet but I burnt the old paint only a coupla inches around the fitting at the bottom. I had to get a new bung made up locally with the correct thread, cant recall the size and pitch now. I borrowed an alignment tool from a local Harley shop to run it thru, align it and silver solder the bung in. I can get the number off the tool in the next few days for ya or maybe someone reading this has one. Its a must to align the threads with the top opening. It also has a tap for cleaning and trueing the threads to match the top as a pilot passes all the way up thru and true. I'd just silver solder a new piece if yours is ruined. Go back to a paint shop and have em mix you a sample of your mix (usually no charge) and after the repairs are done, there would be just barely enough to blow that area back in and cut polish it possibly to blend. At least the good thing is its on the bottom hey? Let me know if you need that gas tank repair tool number and make. You can also thread the tool in to bend the welded piece into alighnment if it welds up and is still out a bit. Its a pretty strong tool for the job. Its pretty well a must, otherwise you need to devise something to keep things true all the way up......Joe

[koanes]

If you are lucky enough to find someone with the helicoil kit in that large size you might be able to repair it that way. Not sure if there is enough metal to work with. If you had to buy the kit it would be cost prohibitive as I'm sure the kit would be over 200.00. A good job shop machinist could probably make you an oversize thread case and sweat it on to your petcock. Or a new petcock with an o/s thread. You would likely have to make a threading tool, similar to an o/s drain plug for an oil pan as well.