Leaking carb

myaddress2020

myaddress2020

Member
I am getting fuel leaking from where the choke rod enters. This is surprising since there is a fuel shutoff to prevent this. Does that mean i have a bad shutoff valve?
 
Presumably the leak is from where the choke rod driver housing enters the carb.
This could be from either 1) a leak permeating through the threads of the driver housing ( it it a tapered thread to try and obviate this potential area of leakage) or 2) possibly cracks in the actual casting around there where some one has tightened the housing in too much. If 1) then goo on the threads such as hermatite helps .. so do a few turns of PTFE tape ( but wait for flack from fordbarners as some don't approve of it!) if 2) then new lower body really is needed.
BUT the shut off valve under the tank should shut off all fuel flow.
(Turning in the GAV in CW firmly won't stop any leak...)
 
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When you shut off the fuel valve there is still gas in the line to the carb. If the float is not set properly, that gas will enter the carb. Try shutting off the valve with the motor running and see if it stops. The motor will eventually die if the valve works.
 
I'd say that if you are getting any leak from the craburettor when the motor is not running, both the float valve and the tap under the tank are leaking. If all were working well, either would stop the leak. Both are an easy fix.
 
That is a common place for a leak to appear in the carb. Also, shutoff valves do wear. They can usually be polished, re-seated, or even just tightened.

Ken
 
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Just a thought.... The float is not set to the right height. The level of fuel in the bowl is to high causing it to level out and leak at the threads.
 
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30ccpickup said:
Just a thought.... The float is not set to the right height. The level of fuel in the bowl is to high causing it to level out and leak at the threads.
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No!
Even if the the fuel level correctly set at 5/8 inch below top of lower body you will find that this IS above the level of the threads on the GAV housing It is essential that the threads of the GAV housing are leak proof.
 
myaddress2020 said:
I am getting fuel leaking from where the choke rod enters. This is surprising since there is a fuel shutoff to prevent this. Does that mean i have a bad shutoff valve?
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I had a leak there when the fitting screwed into the body. The body was cracked. Thus had to get a different body. I think I caused this problem when I screwed the fitting into the body to far being it is tapered.
 
The only product I could find to stop the same leak was the copper coat spray one uses to seal a head gasket. It can be also used on carb gaskets, hence, it works with gas.

Take the carb off of the car, separate the bottom half of the carb from the top half, drain all gas out and make sure the carb is dry. You can then take the GAV needle our of the carb housing. I found it best to spray the copper coat onto an artist brush to apply the copper coat. Use the brush to coat both the threads on the GAV and the carb housing. Replace the GAV into the housing when it is still wet with copper coat and be sure it is tight. Let it sit overnight. You should be good to go.
 
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Dick M said:
The only product I could find to stop the same leak was the copper coat spray one uses to seal a head gasket. It can be also used on carb gaskets, hence, it works with gas.

Take the carb off of the car, separate the bottom half of the carb from the top half, drain all gas out and make sure the carb is dry. You can then take the GAV needle our of the carb housing. I found it best to spray the copper coat onto an artist brush to apply the copper coat. Use the brush to coat both the threads on the GAV and the carb housing. Replace the GAV into the housing when it is still wet with copper coat and be sure it is tight. Let it sit overnight. You should be good to go.
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I hadn't thought of using a gasket sealer in that application. Thanks for the tip. I guess it would help sealing the fuel gauge too.
 
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