Float valve leaking

[jdpalmer]

On a zenith carburetor I have replaced the float valve with two new ones and set it in a jig to adjust the 5/8 level but it keeps overflowing even with three washers. The float checks good too. The only thing I see is a little chunk on the bottom thread. The valves work in another carb so they are good any ideas

[SteveB31]

Often the surface they seal against are pitted. We mill them on Bridgeport so they are smooth.

[Gary WA]

Originally Posted by jdpalmer

On a zenith carburetor I have replaced the float valve with two new ones and set it in a jig to adjust the 5/8 level but it keeps overflowing even with three washers. The float checks good too. The only thing I see is a little chunk on the bottom thread. The valves work in another carb so they are good any ideas

I have never had but one washer on the float valve! try to readjust with just one washer and tighten down good.If you have repo gasket for the two halves the float maybe hitting the gasket when you put it together? they are a lot wider around the float. ?

[TJMack]

Is it possible that the housing is cracked where the valve screws in? I remember fighting with this leaking issue on my first "A" but I can't remember what finally was the fix.

[Tom Endy]

Someone may have molested the float in an attempt to adjust the fuel level. In doing so the float does not come up straight and it cocks the valve and causes it to leak. The fuel level should always be adjusted with washers under the valve, not by molesting the float.

Tom Endy

[Ruth]

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Yeah! Ya gotsta watch out for those Float Molesters.

[160B]

I have found that the float can contribute to the problem. You need to inspect carburetor float hinge bracket, frequently the float valve will wear a dimple in the hinge bracket and the dimple and will impede the float travel and thus not completely seat the needle in the float valve. See the below photos of two floats with dimples from years of contact with the float valve needle.

[heDONist]

After chasing an overflowing carb, swapping out parts and float height. And still not fixing our problem, i picked up the float and shook out. Sure enough i could hear fuel in the float, a pin hole leak was detected.Since replacing the float the car and carb run great, no more overflowing.

[Gary WA]

Originally Posted by heDONist

After chasing an overflowing carb, swapping out parts and float height. And still not fixing our problem, i picked up the float and shook out. Sure enough i could hear fuel in the float, a pin hole leak was detected.Since replacing the float the car and carb run great, no more overflowing.

Nice Thanks for reporting your fix.

[jdpalmer]

Thanks for all the suggestions. I took the float valve apart as one suggestion cleaned it out although I couldn't see any material in it. Put it back together with 3 washers and on gas level stand like Brattons showed on their web. It was two low so I just put2 washers a red one and silver and it came out right on 5/8. Put. In car and it didn't leak so I reckon there was something I cleaned out.

[700rpm]

Make sure the heights of the two jets feeding the venturi are correct.