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two cups of tea
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1,054 Posts
Discussion Starter · #1 ·
I tightend the bolts into the fuel bowl to tight &striped out 2 of them I guess when It went in the main body I went too much do you have any idea what I shoud do?can I buy a new main body?I couldn't find a self threading screw my sisters husband it a machinist&I took it to him&he's taking it to work to try to use a tap&dye&bigger bolt,if that dosent work then what?
 

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More for Less Racer
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20,926 Posts
Don't mess it up with a bigger bolt, a helicoil thread repair is the way to fix it correctly. If he's a machinist and doesn't know what a helicoil is, he's not much of a machinist.

In the future, its a carburetor and gasket, not a lug nut :D LOL, I'm just funning with ya.... Anything tighter than a nutdriver/screwdriver will get it is too tight, and even a screwdriver will kill it if you get carried away. If it don't seal it's new gasket time, not a bigger wrench.
 

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More for Less Racer
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20,926 Posts
Don't know why they said not to use a helicoil, it is what the professional carb restoration and race carb shops use for repair. Sometimes local shops can be pretty clueless. Your guy should know how to do the helicoil with his experience.

Either fix will work, you just might have trouble finding a bigger screw the right length and with the underhead washer built in to seal against the bowl screw gasket.
 

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WFO
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5,030 Posts
cutthroatkid said:
Idk Im 16 still learnig they said something about the fuel &the coil something about it woll still leak idk?
The helicoil holes need to be drilled straight, and not so deep as to hit air OR fuel- this is done by measuring the depth of the holes as they are now, then drilling to the same depth w/the larger drill bit.

This is done to a disassembled carb w/at least a drill press (not by hand w/a cordless drill, unless it's an emergency repair), so either the bit or the press can be set up w/a stop to keep the hole from being taken too deep.

From that point, it's a straightforward helicoil repair. Care is used because the carb is zinc- softer than steel and somewhat brittle. But nothing that can't be successfully done by a competent individual.
 

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two cups of tea
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1,054 Posts
Discussion Starter · #8 ·
I went&looked @ the kits I yup you're right...but I allready gave it to my sisters husband so idk????he's been [email protected] a custom bike shop forever&he runs drag bikes so I'm thinking he should be able to fix it,He did mention something about the plastic washers but said he would be able to come up with something,he's had a couple of novas too so idk???now I'm wishing that I would of got that kit first but I won't be able to get ahold of him before he gets to working on it.What if it leaks after he changes the bolt to a wider one?Then will it be too late to use. The kit?uhh this is expensive I put every dollar I have into this thing,once I paint it its gonna be killer!I just wanna go race this weekend&have a blast!
 

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WFO
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5,030 Posts
cutthroatkid said:
I went&looked @ the kits I yup you're right...but I allready gave it to my sisters husband so idk????he's been [email protected] a custom bike shop forever&he runs drag bikes so I'm thinking he should be able to fix it,He did mention something about the plastic washers but said he would be able to come up with something,he's had a couple of novas too so idk???now I'm wishing that I would of got that kit first but I won't be able to get ahold of him before he gets to working on it.What if it leaks after he changes the bolt to a wider one?Then will it be too late to use. The kit?uhh this is expensive I put every dollar I have into this thing,once I paint it its gonna be killer!I just wanna go race this weekend&have a blast!
There are several possibilities.

One is that he'll use helicoils in the first place, after he sees what he's dealing with.

Another possibility is that the larger sized screw he uses will actually be the correct size for a helicoil insert. Or, the larger sized screw will still be smaller than the required threaded hole for a helicoil, so an insert can still be used.

Or, the repair he does works by using a larger screw, w/o drama.

Or, he totally trashes the carb body, leaving you carb-less until you find another used body or buy a new body.

You will know soon enough.
 

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Old(s) Fart
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6,014 Posts
cobalt327 said:
Better yet, just go buy the inserts for like $10 and use your own drill and tap.:rolleyes:
Helicoil taps are non-standard, so unless you have a helicoil kit already, it's doubtful you will have the correct tap. Since the helicoil insert is simply a helical coil of diamond-cross section wire, the outer thread pitch is the same as the inner thread pitch, thus the need for a custom tap. Most helicoil kits come with the correct tap, installation tool, and inserts. You usually need to supply your own drill bit anyway.
 

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WFO
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5,030 Posts
joe_padavano said:
Most helicoil kits come with the correct tap
Thanks for that- I have a a "few" helicoil taps/inserts and never much gave a thought to it.

Might be worth mentioning- Helicoil brand is not the only game in town- Cal Van carries "helicoil-type" spark plug repair kits (possibly others), and Balkamp (NAPA) are actually Helicoil brand.

The other loose inserts and other helicoil taps are in another area.
 

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Old(s) Fart
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cobalt327 said:
Might be worth mentioning- Helicoil brand is not the only game in town- Cal Van carries "helicoil-type" spark plug repair kits (possibly others), and Balkamp (NAPA) are actually Helicoil brand.
Correct. Also, helical coil type inserts are not the only type of thread repair insert. One of the criticisms of Helicoils (and the like) are that they can back out when you try to remove the fastener. In the aerospace industry we use Keenserts (that's one brand name - there are others). These are solid machined thread inserts with locking tangs that are driven down into the parent material after installing the insert to prevent it from backing out. Unfortunately, since Keenserts are machined, they have a larger OD than the same size Helicoil. This can be a problem if the threads being repaired don't have much edge distance.
 

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Evil Wicked Mean And Nasty
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13,765 Posts
ericnova72 said:
No. If he is doing it right with a helicoil it will be putting the threads back in the correct position for the original length bolt.
Eric is right on, And it sounds like someone is missing something here, As eric said all you are doing with a helicoil is replacing the threads thats all. Sounds to me like you would be just as good fixing it yourself just take your time and make sure its good and straight when tapping it out for the coil.JMO. Cole
 

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WFO
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5,030 Posts
joe_padavano said:
Also, helical coil type inserts are not the only type of thread repair insert.
Right on the money.

But w/the repair the OP's considering, a heli-type repair is the best bet, IMO- due to the lack of material that you mentioned in the area of the bowl fasteners.

You mention the aerospace industry. I was amazed the first look I got at the day side casting for the TAD/PNVS set-up used on the Apache.

The titanium castings were then coming in to us at Martin Marietta, Orlando from Germany. They were beautifully finished w/every threaded hole inserted. Really nice workmanship.
 

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WFO
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5,030 Posts
cutthroatkid said:
He said that when I strippd it I made the hole deeper
If you consider that statement for a minute, you will realize that it's really quite impossible to make a threaded hole deeper by stripping the threads. Wider by a bit perhaps, but not deeper.

The Holley screws are somewhat unique themselves in that the underside of the heads are sized so that the necessary gasket/seal- that HAS to be used to prevent fuel leakage- fits and is supported properly.

The bowl screws, seals and the corners of the fuel bowl that "capture" the seals are a matched set, so to speak. To materially change any of it w/o maintaining the integrity of the seal, risks making the carb into a leakage-prone fire hazard.
 
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