Broken Carburetor Jet

DJ S

DJ S

Well-known member
So I purchased a Zenith Carburetor at a swap meet over the winter and I decided it's time to rebuild it. As soon as I opened it up, i see that someone had attempted to remove a jet and the secondary well and broke the jet and mangled the slot on the secondary well. The only solution I see is soaking it in carb cleaner for a week or so, spraying it down with PB Blaster and trying to get them out with an ez-out. Is that the best route, is there a better route, or is the carb junk?
 
I know this sounds like it will break the casting, however it does not...
Heat the casting around the jet to a DULL red with an oxy acetylene torch, preferably using a rose bud tip. Then using a welding gloved hand and a large pliers, dunk the carb into cool water. There will be a lot of hissing and popping, however the jets will be loose and easy to remove. On the broken ones use a easy-out if you can. I have rebuilt many, many carbs and always use heat and cool water, have never broke a carb casting and have never twisted off any jets.

The heat only to a dull red is very important, bright red and the brass jet will melt and you will have a bigger mess. DO NOT heat on the brass parts, they melt.
 
A guy in our club tried an easy out to remove a stuck jet and broke it off. Ended up having to spark erode it. Personally, carbies are plentiful and cheap so I wouldn't spend much effort on it. Might be easier to rebuild the one on the car using the tips above to get the jets out.
 
You might try soaking the carb in ammonia. Ammonia dissolves brass. It might take some time to work on something as large as a jet, but it's worth a try. This will also dissolve the passage plugs in the carb body, which will allow you to clean them out very well. But you'll have to put new plugs in.
 
it has been my experience that heat and cold water dunking will allow easy removing of stuck parts on a Zenith. When I start a restoration on a Zenith I try to remove as many parts that will come apart without forcing. For those that don't. I heat the casting with an acetylene torch until there if a faint glow in the area where a part is stuck. Immediately dunk the entire casting in a bucket of cold water and leave it until it is cooled. Sometimes I have had to repeat the process three or four times in a particular area to get it to come apart easily. The most stubborn are the secondary well. the GAV assembly, and the brass GAV seat if one is installed. The screws in the throttle plate and choke plate are the easiest. They turn to a red glow immediately and are always then easy to remove unless the guy before you butchered up the screwdriver slots. The jets usually only require one heating and dunking.

From what I understand the process expands the two different metals at a different rate and then the dunking shocks them loose. Works every time for me.

Tom Endy
 
I had one that was drilled out but now hole was oversized,I sleeved the hole and tapped it for the jet worked out fine.
 
DJ S.... I did what the others are suggesting too, and it does work---- heat the area of the carb you want to disassemble with a hot torch then quench it in a bucket of cold water.

I don't have an acetylene torch only a map torch and it worked well. I did 6 Zenith and Holley carbs last summer that I bought at an auction of Model A parts, and never cracked a single casting. As Tom said, the secondary well can be a booger I had to reverse drill two of them out but they popped right out no problems.

When you are ready to rebuild, I would buy flo-tested jets from Renners. Don't mess with what most of the vendors sell they are usually off. I got a set from them and man what a difference!! Car runs like it is supposed to:):)

http://www.rennerscorner.com/carburetor.html
 
I agree with the method of heat then cold. Makes them loose so they will remove more easily. You may not have a torch. Make sure all the gas has evaporated, then put it on your gas grill on high for about a half hour. That should run it up over 500 degrees. Then drop it in a bucket of ice water.
 
Big hammer said:
I'm wondering what you used and how you installed the sleeve ?
Inquiry minds would like to know :-)
Click to expand...

Interesting, I would like to know as well how you did it. On the occasions where I have encountered a Zenith that somebody drilled the jet out and molested the threads my only option if I wanted to save the casting was to JB weld the jet into place, Not desirable, but a last resort.

Tom Endy
 
Tom Endy said:
Interesting, I would like to know as well how you did it. On the occasions where I have encountered a Zenith that somebody drilled the jet out and molested the threads my only option if I wanted to save the casting was to JB weld the jet into place, Not desirable, but a last resort.

Does the JB Weld hold up when bathed in gasoline? I had thought that it would eventually break down.
Click to expand...
 
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