carb

[DanR]

Is it feasible to put a heli-coil in the carb for the fuel line?

[Phillip W. Lenke]

Yes!
The helicol kit will be the most expensive part.
1/2-20
Thread
Phil

[DanR]

Thanks, that's what I wanted to know.

[Rudi]

Yes!
The helicol kit will be the most expensive part.
1/2-20
Thread
Phil

Phil:

By any chance, could you/would you pretty please... post exactly how to do it? I woulld like to fix Ellie's carb properly and put on the steel gas line. I have never used a Heli-coil Kit and I want to learn..

All help is appreciated. I think I have access to a kit and the parts are relatively cheap after the kit is factored out!

[cjpenny89]

I fixed 2 carb's before I sold them on ebay it was very easy. I borrowed a flat bottom tap and helicoils from Dennis79 on this site. I just sent it back to him when I was done. I would not hessitate to do it.
Rudi
buy the kit it is very self explanitory and comes with everything you need.
the special tap that dennis79 sent me was a special flatt bottom tap so you could get the threads all the way down. IT was very very easy to do and took less then 5 minutes.

[Jim Becker]

A 9/16-12 bottoming tap? That is a standard size. I thought you needed an odd size for the helicoil threads. Something bigger than 1/2 in a 20 pitch? Have you found a different type of insert?

[cjpenny89]

Jim
I am sure that it was a 9/16 but maybe it was a 5/8. the special part about it was he took and made it so it was a flat bottom bore otherwise you could not get the new threads deep enough.

Off to the shop to see what szie the 1/2-20 helico uses. I will report back. Sorry if I said the wrong thing.

[cjpenny89]

Jim your right its a odd ball sorry for the confussion

[Phillip W. Lenke]

I bought a special Kit
I would really wonder if it is a standard thread.
Would save a ton of money.
I bought two taps one for starting and cut one to bottom tap as in the previous post.
However the set up took me longer than 5 min. I have a fixture I bolt to and indicate the 5/16 dia below the ferrel seat.
Would be interested in the 5 min class
Phil

[George Willer]

Phil's method is the right way to assure the threads are concentric with the ferrule seat. Other methods can work, but they're "iffy". This is especially true when using a tap without the starting taper.

[cjpenny89]

well ok maybe more then 5 minutes but it didn't take long at all. I used the starter tap then the flat bottom that he sent me. It was easy. The threads were already screwed up I had nothing to loose and it went easy.

[Rudi]

Questions:

End mills - can they be used in a 1/2 shank Drill Press? I don't own a milling machine and I seriously doubt I ever will?

What End Mill would be appropriate?

What type of jig would be useful to make to do repetetive boring for carb fuel inlet thread repairs? I would think a jig similar to George's Carb Straightening Jig, but maybe with a base plate to secure to the Drill Press table? I have 3 to do, and I imagine probably a host of em that are around here would benefit.....

Can a novice metal worker do this with out totally destroying an almost irreplaceable carb

Phil, should I send my carb and it could be a guineau pig

[Phillip W. Lenke]

Rudi
I sent you a PM.
as far a a drill press the only caution I would give ,would be have the carb as stationary as possible. And use slower RPM with more flutes. 1/2" end mill will work but it must be a single end-Flat endmill.
Holding them tight with out undue stress on the carb body is the key.
Important when you tap, this is the most stress you will have, don't rush the tapping, I have not broke a carb yet BUT! you never know. so I cut one turn back it out . blow it out and lub up good and cut again.
I have done, I'm guessing 5-10 carbs and seem to have turned out OK.
I did some for George and BD have been happy with the work ,So I'll continue with what works.
Phil

[Donny M]

Rudi
I sent you a PM.
as far a a drill press the only caution I would give ,would be have the carb as stationary as possible. And use slower RPM with more flutes. 1/2" end mill will work but it must be a single end-Flat endmill.
Holding them tight with out undue stress on the carb body is the key.
Important when you tap, this is the most stress you will have, don't rush the tapping, I have not broke a carb yet BUT! you never know. so I cut one turn back it out . blow it out and lub up good and cut again.
I have done, I'm guessing 5-10 carbs and seem to have turned out OK.
I did some for George and BD have been happy with the work ,So I'll continue with what works.
Phil

Don't forget the 3 you did you me
Nice work