Zenith Rebuilt Problem

JOES31

JOES31

Senior Member
Is it common to purchase a rebuilt Zenith Carburetor only to have it leak out of the choke throat after you shut it down? I would assume the float is set too high and it was not tested before it left the rebuild shop. Ruling out a bad float valve, bad casting, contaminated gas and float not set right is there anything else that would make these things leak other than a poor design?
 
If the main jet and cap jets were not tight it would leak.
I've read several times that even a new float needle valve has been known to leak.
 
I always try to use original numbered jets. In the past, some main and cap jets have been too short and caused leaks. Sometimes when a carburetor is dismantled, the old main jet gasket is left in the housing. If more than one gasket remains under the main jet, it will alter the height of the jet and cause leaks. Tom Endy has mentioned finding metal particles inside the new float valve assemblies. If the level of the gas in the bowl of the carb is higher than the tops of the main and cap jets, as in an incorrect float level setting, gas will continue to drip out the tops of the jets.
 
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I rebuilt a Tillitson I had and just installed it. The car runs much better and no leaks. Looks like it is a much better carb. I guess I'll use the Zenith for a backup when I get it back.
 
.....All rebuilt carbs should be fully tested before they are sent out to customers; obviously some are just just rebuilt and not checked....
Her's the hit list.....
Zeniths:Causes of leaking Problem: Remedy
1 Leaking/loose float valve gasket: Tighten/reseal/replace
2 Leaking float valve: Replace
3 Friction on float hinge: Loosen
4 Incorrectly set fuel level: Re-set
5 Hole in float: Repair or replace
6 Cap jet or Main jet too short/ more than one gaskets on main jet: check
7 Leaking/loose gasket at main jet: Tighten/reseal/ replace
8 Leaking /loose gasket at cap jet: Tighten/replace
9 Leaking or loose GAV housing threads: Tighten/ reseal/ replace
10 Leak at fuel inlet union: Tighten/reseal/replace
11 Loose/leaking gasket at strainer: Tighten/reseal/replace
12 Loose/leaking gasket at drain plug: Tighten/reseal/replace
13 Cracked housing/leaking passage plugs: Repair or replace

1-6 will generally manifest as poor running.
7-13 will generally not affect running unless there is excessive leaking
 
Send it back! You as a customer of whoever should not accept anything less than what you paid for.....
 
It will keep leaking. I would say the float is set too high. I would shim it but in the instructions it says not to try and fix it if there is a problem because it will void the warranty. The supplier I bought it from, (highly recommended in the posts on this website), is issuing a call tag and is going to replace or repair.

I just can't believe they don test these before they send them out.
 
In shipping the float could bounce around in the empty bowl of the carburetor and get bent out of adjustment. If a spare carburetor gets hauled around for an emergency, it is not unusual to have to readjust the float before use. People that have worked with carburetors can set the float by eye and will need no gauge. With the Zenith carb there is only one bolt to remove. In this case the best thing to do is send it back rather than voiding the warranty.
 
Purdy

That is what I figured. I'll bet the float got tweaked from shipping. I have two other Zeniths and a Tillotson. I rebuilt the Tilly and it works great after fixing the massive gas leak. The other two Zeniths I rebuilt with the help of you guys on the forum and they work fine. I had a third zenith that was old and cruddy so I figured I would turn it in for a rebuilt.
Should have done it myself.
 
The problem has to be in the float valve. If your valve is shutting off no fuel can enter the bowl and flow out. If you are getting very small particles of dirt out of your tank the valve will continue to weep. If that is the problem your new carb is going to seem just as poorly rebuilt. I would check the float level before sending it back.
 
If the carb. was on its side sometimes the pin holding the float will slide out of the float and will make the float level wrong. This make so the needle valve doesn't shut off right.
 
To keep anything coming from the tank and into the carb I installed a filter in the bowl and another in line filter. With two filters it should be ok. I called the supplier and they said not to do anything but send it back. It's on its way.
 
Ok
I got the replacement rebuilt carb back from the supplier and guess what. Most of the threads for the fuel line are missing. The threads start about 3/16 of an inch into the outlet. The starting threads are just about gone.

Oh what quality control. So it's going back for another one. Meanwhile the Tilitson is running great. Maybe I'll dump the Zenith after I get it back. What a poor excuse for a carburetor or should I say carburetor rebuild. Not much difference.
 
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