JB Weld and Carburetors

I've never used JB Weld before, but as I recall, you can drill and tap this stuff, right?

In an effort to be really thorough in my Honda Mini Trail project: http://grassrootsmotorsports.com/forum/grm/71-honda-ct70-mini-trail-vintage-pit-bike-update/1645/page1/

I managed to strip out two threaded holes in the carb while cleaning it and putting in new o-rings. I'm not sure if its white metal or aluminum. On one of the bad holes, I can just run a longer bolt straight through, but the other is a blind hole. I was going to drill and tap for the next size up, but I'm not sure how much material is there.

Can I use JB Weld for this, or is there another option (besides a new carb)?

Small stuff like that I usually go with as small a threadsert or helicoil as I can get away with, even smaller than the original size if need be so long as the outside of the insert is as close to the original size as I can get away with. Easy enough to get a new, stronger little bolt (I like titanium myself) and you don't have to change or damage much.

Loc-tite had a product on the market a few years ago that was made for just such occasions. Unfortunatly I cant remember the name of it but you put this goo in the hole and then put a release agent on the bolt and loosly assembled the part, the stuff cures in the hole and you can tighten the bolt and remove it later. Havent seen it in a while tho but Im sure its still out there. Of course the proper way would be a Helicoil....... Or maybe Miata?

This is for a tiny, fine thread screw and there's not a lot of metal around it, so I don't think a Helicoil is an option. I'll look for the Loc-tite stuff.

Check McMaster-Carr for tiny helicoils, all the way down to #2 or 3mm.

One more option might be to replace the blind one at least with a stud if you can. It could be threaded in to any threads still remaining beyond where you stripped them and you could use a quality epoxy or whatever to lock it in place.

I pretty much work on the principle that if it's soft metal and I've stripped it once then it needs inserts or studs so I won't do it again. I always say I'll be easier on it next time, or just more careful, but I really know better.

JB weld does work in carbs. A fellow rare snaped off a Float Ear casting on a $300 racing carb. We JB welded it at the track three years ago. It's still running fine

Helicoils are the best fix of threads.

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porksboy wrote: Loc-tite had a product on the market a few years ago that was made for just such occasions. Unfortunatly I cant remember the name of it but you put this goo in the hole and then put a release agent on the bolt and loosly assembled the part, the stuff cures in the hole and you can tighten the bolt and remove it later. Havent seen it in a while tho but Im sure its still out there. Of course the proper way would be a Helicoil....... Or maybe Miata?

Have used the stuff in a non-stressed bolt hole. It did not work, still have some left somewhere. I would not suggest it.

I chose to take the non-GRM route and ordered a new carb. Thanks for the suggestions, though.

For scientific purposes...did you try the JB Weld? Since you've got another carb, no hurt in trying. Heck, it'd be nice to have a spare carb ready to go if it actually works, should you ever have a problem with the new one or find somebody else who needs one.

Bryce

I will try some type of repair after the new carb gets here, just out of curiosity. As for hanging on to the old one for a spare; these carbs are notoriously "not worth fooling around with". It takes less than five minutes to swap one completely, though, so I'll give it a try after the fix.

Update:

When I swapped the new carb on, I found that the old one had already been helicoiled once. Looks like it was probably time for a new one anyway.