The Ford Barn - View Single Post - Zenith Carb leaking, what type of needle value to get

Houdini · 06-01-2017, 07:27 PM

I have a Zenith carb in my 31 Slant Windshield A.

It had been working fine. I opened up my sediment bowl to install a new gasket the other day. I have a shutoff just past my sediment bowl. After I got the bowl so it wouldn't leak after the new gasket (another story), I found when I turned on the fuel. I had a pretty bad leak at the carb.

It took a few minutes before I spotted fuel leaking under it. I turned off the shutoff and found the bolt that holds the body together on the carb, was not real tight and snugged it up. then turned the fuel back on.

it took a couple of minutes and then the leak started again. I decided that the fuel was not leaking from the bottom but running down the outside of the carb, to the bottom, perhaps out the intake area, not sure.

From what I know from the previous owner, the carb was a rebuilt one about 18 years ago and has been fine so far. I'm thinking that somehow after opening up the fuel line path by the sediment bowl, that maybe the needle valve under the float came down and is now not seating properly, including some wear.

My next step is to take the carb off and install a new needle value as well as look for anything else that is obvious (to my untrained eyes).

I see in Bratton's catalog for Zenith, they carry 3 different needle valve assemblies. One is said to be like the original, the second one is a fuel resistance rubber tip and the 3rd one is a steel ball against an O-ring.

Any suggestions on which needle value to get, and any other suggestions as to what might be causing the leak. Again it wasn't doing this before the sediment bowl work. It leaks enough to form a small puddle after a few minutes, so I don't want to start it with that much of a fuel leak.

06-01-2017, 07:27 PM	#1
Houdini Senior Member Join Date: Jul 2015 Location: Central Texas Posts: 113	Zenith Carb leaking, what type of needle value to get I have a Zenith carb in my 31 Slant Windshield A. It had been working fine. I opened up my sediment bowl to install a new gasket the other day. I have a shutoff just past my sediment bowl. After I got the bowl so it wouldn't leak after the new gasket (another story), I found when I turned on the fuel. I had a pretty bad leak at the carb. It took a few minutes before I spotted fuel leaking under it. I turned off the shutoff and found the bolt that holds the body together on the carb, was not real tight and snugged it up. then turned the fuel back on. it took a couple of minutes and then the leak started again. I decided that the fuel was not leaking from the bottom but running down the outside of the carb, to the bottom, perhaps out the intake area, not sure. From what I know from the previous owner, the carb was a rebuilt one about 18 years ago and has been fine so far. I'm thinking that somehow after opening up the fuel line path by the sediment bowl, that maybe the needle valve under the float came down and is now not seating properly, including some wear. My next step is to take the carb off and install a new needle value as well as look for anything else that is obvious (to my untrained eyes). I see in Bratton's catalog for Zenith, they carry 3 different needle valve assemblies. One is said to be like the original, the second one is a fuel resistance rubber tip and the 3rd one is a steel ball against an O-ring. Any suggestions on which needle value to get, and any other suggestions as to what might be causing the leak. Again it wasn't doing this before the sediment bowl work. It leaks enough to form a small puddle after a few minutes, so I don't want to start it with that much of a fuel leak.