Author Topic: Carb stem crack, fixable?  (Read 1357 times)

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Offline ncstatecamp

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Carb stem crack, fixable?
« on: July 21, 2012, 03:45:44 PM »
It's not all the way around and the threads are still fine. Can I just Jb weld it?

Offline lucky

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Re: Carb stem crack, fixable?
« Reply #1 on: July 21, 2012, 04:23:53 PM »
Did it happen from over tightening? Just asking.

The  brass part (emulsion tube) that goes inside will help hold it together.
What I would do is use gas proof epoxy. I think JB weld is gas proof but not sure.
I would read the package.

I would sand the outside until it is clean shiny aluminum so that any epoxy on the outside is helping to make it stronger. Apply the epoxy carefully with a tooth pick.

Then I would thread in the brass part coated with WD40 (finger tight) so that the threads do not get jammed with epoxy.

That piece that is cracked establishes the depth of the emulsion tube.

Make sure to spray those other jet threaded holes with some WD40 too.

« Last Edit: July 21, 2012, 04:30:01 PM by lucky »

Offline scottly

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Re: Carb stem crack, fixable?
« Reply #2 on: July 21, 2012, 06:48:48 PM »
JB weld will not hold up submerged in fuel. A member here might be able to weld it; Jim F.
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Offline ekpent

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Re: Carb stem crack, fixable?
« Reply #3 on: July 21, 2012, 07:18:35 PM »
I have fixed one before on the cheap by using a 45ACP cartridge. Here are some quickie details.  http://forums.sohc4.net/index.php?topic=100144.0

Offline ncstatecamp

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Carb stem crack, fixable?
« Reply #4 on: July 21, 2012, 07:38:50 PM »
Did it happen from over tightening? Just asking.

The  brass part (emulsion tube) that goes inside will help hold it together.
What I would do is use gas proof epoxy. I think JB weld is gas proof but not sure.
I would read the package.

I would sand the outside until it is clean shiny aluminum so that any epoxy on the outside is helping to make it stronger. Apply the epoxy carefully with a tooth pick.

Then I would thread in the brass part coated with WD40 (finger tight) so that the threads do not get jammed with epoxy.

That piece that is cracked establishes the depth of the emulsion tube.

Make sure to spray those other jet threaded holes with some WD40 too.

I'm not sure if it was over tightening or what. This is my first bike build and I bought a big pile of parts 2 sets of frames motors wheels etc from a guy. One of the other carbs had a broken float stem so I'm pretty sure it's seen some dimly treated days. Will wd-40 protect the jet holder from being expoyed in place?

Offline ncstatecamp

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Carb stem crack, fixable?
« Reply #5 on: July 21, 2012, 07:39:22 PM »
JB weld will not hold up submerged in fuel. A member here might be able to weld it; Jim F.

What about the epoxy tube stick stuff?

Offline Frostyboy

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Re: Carb stem crack, fixable?
« Reply #6 on: July 21, 2012, 07:46:53 PM »
JB weld will not hold up submerged in fuel. A member here might be able to weld it; Jim F.

http://forums.sohc4.net/index.php?topic=18649.0
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