Leaking Carburetor leak found HOW can I fix this?
 

So, I found my carburetor leak, the cap jest is stripped out and leaking, the bottom of the carb is striped out. Are there oversized Cap jest or a way to insert a new thread into the bottom?

Any Idea apreciated.

Cheers

Re: Leaking Carburetor leak found HOW can I fix this?
 

J-B Weld if nothing else is offered.

Re: Leaking Carburetor leak found HOW can I fix this?
 

I think that is what they had used before and it let go.

Cheers

Re: Leaking Carburetor leak found HOW can I fix this?
 

I would use a helicoil but I don't know what size the tread on the Cap jet is.

Re: Leaking Carburetor leak found HOW can I fix this?
 

Omit.

Re: Leaking Carburetor leak found HOW can I fix this?
 

I don't see a PM

Re: Leaking Carburetor leak found HOW can I fix this?
 

I might be wrong but I think the threads on the jets are metric.

Re: Leaking Carburetor leak found HOW can I fix this?
 

I don't think a JB Weld fix is going to get it tight enough to not leak and the tip of the jet might not be at the correct height. I vote for getting a new casting.

Re: Leaking Carburetor leak found HOW can I fix this?
 

LOOK ON EBAY. THEY HAVE A BOTTOM CASTING FOR $49.99. Search "model A zenith carburetor on EBAY".

Re: Leaking Carburetor leak found HOW can I fix this?
 

this is the best way to go. i hope this works for you.

Re: Leaking Carburetor leak found HOW can I fix this?
 

They are, plus they are pipe-thread. I bet some do-gooder taped it.

Get another lower casting.

Re: Leaking Carburetor leak found HOW can I fix this?
 

Cavalier home

Do you have a Zenith carburetor?

Re: Leaking Carburetor leak found HOW can I fix this?
 

Yes it's a Holley I think.

Re: Leaking Carburetor leak found HOW can I fix this?
 

There is an article in the current Restorer magazine for repairing threads in the carburetor casting with Helicoils.

Re: Leaking Carburetor leak found HOW can I fix this?
 

Some years back I repaired the cap jet threads in a Zenith by applying a coating of JB weld. It worked well. Attached article describes the jets threads used in the Zenith.

Tom Endy

Re: Leaking Carburetor leak found HOW can I fix this?
 

So I think I found a good way to fix the Jet issue.

I didn't want to go with helicoil because they allow fluid to leak passed the threads I think.

I decided on time-sert

I found out the threads on the Cap jest are 5mm .75 pitch

I was not able to find a time-sert in 5mm .75 pitch, but I could find 5mm .80 pitch, so I figured they are so close I could just chase the time-sert with a .75 pitch tool.

It turns out the jet is pipe tread and works perfectly with the .80 pitch time-sert.

So I threaded the jet location for the time-sert an used an old jet to chase it in.

It seems to be fine, and I hope it works well.

It seems to hold vacuum but it is hard to tell because there are so many ways that passage receives fluid. If it still wants to allow some small amount of fluid over the long term to get passed the threads I will remove the time-sert and reinstall it with some ultra copper RTV. I have used that stuff to fix all kinds of leaks on race cars and it works. But I want to test this without it at first to see

I have the carb ready to go except the secondary well didn't come with the rebuild kit so I have one coming in.

Once I finish that I will try the carb and see if it still leaks gas while parked.

I will let you all know, and if it works I hope this helps somebody else someday.

Re: Leaking Carburetor leak found HOW can I fix this?
 

That sounds good
question though, isn't a 5mm x .8 an IMP 10-32?

I know on machinery I have seen 10-32 and 5mmx.75 interchanged.

John

Re: Leaking Carburetor leak found HOW can I fix this?
 

Sincerely I don't know but it might be worth finding out.

Re: Leaking Carburetor leak found HOW can I fix this?
 

Seems o be similar but not exactly the same:

https://www.emuge.com/sites/default/...ill-CardV5.pdf

Re: Leaking Carburetor leak found HOW can I fix this?
 

Latest Restorer has an article on installing inserts.