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Discussion Starter #1
I'm rebuilding my 4100 carb and found a dent in the top edge of the carb body. It's about .020" deep and 1/4" long. It looks like a hammer taped it.
I need to build it up so it will seal to the top plate of the carb. I don't think JB weld is gas resistant so I'm looking for options. Any ideas?
 

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With the gasket installed, I don't think it will be an issue. The carb will actually run without the air horn / top cover on, though I wouldn't drive it that way of course. If you have to fill it, try a small amount of Quik Steel. It is a two-part putty. Pinch a little off, roll it together, and mould it to the shape you need. It can be sanded, ground, filed, welded on, primed and painted even. It works great on aluminum. I have used it on oil pans, timing covers, headlight doors...
 

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"I" would start by squeezing the area with vice grips to "push" some of the aluminum back into the area if possible. You can't chance hammering it back into place as it is a die casting and somewhat brittle. You could then fill the low sport with a gasoline resistant epoxy product like JB weld and carefully file it flat as suggested above. If it's flat , it will seal. There is a low temp aluminum "solder" that works well under the melting point of aluminum but is too expensive for such a small repair.
Randy
 

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Discussion Starter #6
I have some Alumaweld, but lm not going to chance using it. With my luck I'd make it worse. I'd like to peen or squeeze it back into shape, but I'd still likely have add epoxy to level it. I've never tried Quick Steel. I do have JB Weld, but is it fuel resistant?
 

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Yeah I think once Qwik Steel goes through its heat process, it's THERE.
 

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I have used JB weld on carburetors and it stood up to 100LL gas.
 

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Put the gasket and lid on and see if it seals. If not, put some JB on top of the lip and file it smooth.
 
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Discussion Starter #11
I've never seen anything like Muggyweld! Very interesting. I already have JB Weld so I'll give it a try.
Thanks everyone!
 

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20 thou? The top gasket will take that up np. If you are really worried about it I would put a swipe of a fuel resistant RTV and call it a day. Permashield from Permatex will work. For me, I would just put the gasket on, torque to spec and see it you get a leak there after driving. The bowls are vented to the air anyway so all you are really trying to do here is not have gas run down the outside of the bowl.
 

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Lightly rough up the surface and JB Weld it-file it flat. You'll never have an issue with it again in this instance as the JB is impervious to fuel (even long term.).
 

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If one gasket does not work, add a second with a dab of fuel resistant sealant at the low spot.
 

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RTV stands for Room Temperature Vulcanizing, but in the common parlance is associated with any of the gasket making or sealing compounds.
743164
 
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Discussion Starter #18
Please let me ask another question about my carb.
This is another situation with my carb that I'm not sure about the best course of action. It looks like a sheet metal screw is glued into the idle adjustment. How would you deal with this?
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Wow that’s a mess. Those are not idle adjustments. Those were access ports used to drill out passageways during manufacturer. They are then plugged. It looks like the plug fell out of one and someone tried to fill it with the screw and rtv. It appears cracked/damaged as does the one next to it. That screw needs to come out and both need to be properly sealed up.

What model carb do you have?
 

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The crack above the screw is a problem. It might not go all the way through. The left one just looks like dirt and not a crack. Start by removing the screw and shining a bright light on the inside of the carb to see if that crack goes all the way through. If it does not. I would get a flat bottom tap of an appropriate size and tap it out. Might want to do that with a vacuum collecting chips. Plug with a set screw with a little bit of that Permashield or other fuel resistant sealer. If you have one of those stupid bright LED tactical flashlights, that would be a good source for checking that crack. A dark room will also help.
 
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