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One of the screws that go along the top perimeter of my carb is stripped on my '41; is the helicoil still the way to go or is there a better method to fix stripped threads? 

Thanks!

Peter

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You can always try tapping further into the hole, and using a longer screw; but if that fails (opinion) the heli-coil is the best option.

 

Jon.

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Thanks Jon. I'm thinking you are the best person to ask (or respond). 

Peter

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Valk,

Have you considered "JB Weld" ?

Mix it up, shove in hole and add screw (gently).

It should conform to the screws threads as it "sets".

 

Mike in Colorado

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Can you run a thread chaser down the hole and see if the threads come back? A heli-coil would be just fine but you might be able to bring them back if they're not totally gone. Those old castings don't have a lot of strength but you might be able to get enough material so the screw can bite. They don't have to be really tight, just enough to seal the gasket. As much as I like and respect my friend Mike, I think I would try to avoid the JB Weld as anything but a dead last resort. Think of the poor schmo after you who tries to disassemble that carb...

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Thanks boys. I kinda agree JB weld would be great if I didn't have to use the screw again but I need to be able to remove and insert the screw many times. I'll try restoring and/or extending the threads but I think ultimately I'm headed for a heli-coil which I've used many times successfully. 

Thanks again.

Peter

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 Matt, Valk,

We have used JB on Harley side cases lots of times.

Both to fill the hole, drill and re tap, and as roadside repairs where we shoved it in the hole and ran the screw right in before it hardened.

We wiggled the screw a couple of times AS it hardened, so it would not "bond" to the threads.

We could always get the screw out back at the shop.

 

Mike in Colorado

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I think the key to the JBWeld is getting the screw out before it hardens completely.   Maybe practice on something first.  Consider using a piece of allthread instead of a machine screw so that you could put a nut on the top if you had to.   

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Posted (edited)

I have used "Plastic Steel" before there was JB Weld. I would put the epoxy in the hole, grease the screw and screw it in. Torque after the epoxy hardened. Always came out clean. Typical repair on valve cover bolts.

 

Then I discovered Helicoils....😉

 

Edited by Frank DuVal (see edit history)
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Yes. Why wouldn't you use a helicoil? Epoxy is really sketchy around gasoline. Even if not around gasoline, it's still a kludge to use it on threads. The only reason I can think of to try epoxy is if there isn't enough metal around the hole to drill oversize for the helicoil.

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Epoxy has worked for me as Frank described  (light duty), but a helical works best were torque is needed,

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1 hour ago, Frank DuVal said:

I have used "Plastic Steel" before there was JB Weld. I would put the epoxy in the hole, grease the screw and screw it in. Torque after the epoxy hardened.

The trouble with that is that the threads are only as deep as the length of the screw/bolt, as the epoxy will flow under the end of the screw.  Which is to say you're not really torqueing it down; you're bottoming out.  IOW, you'd need to use a piece of allthread or a longer bolt (or take the washer off the screw) to make sure the threads are deep enough.  Plus, if you're using this to repair a hole that's used to clamp two parts together, you may have issues with the epoxy squeezing out of the hole and between the mating surfaces.

 

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My '41 fuel pump was leaking from one of the many screws that hold on the diaphragm section.

The man who rebuilt it put a heli-coil and it has held nicely. If you don't want to order a whole

batch of them just go to a local machine shop and see if they will sell you one or two.

They always have them on hand in the tool room.

 

Regarding JB Weld, I once cut through a seized fitting that was on an outdoor water hose spigot.

Unfortunately I managed to cut through an outer thread on the spigot.

I then covered the thread and small hole with JB-Weld, lightly screwed on the garden hose, and then removed

the hose. The next day the hose went on nicely. There is a tiny but acceptable leak, though.

Way better than before.

 

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