Odd Fuel Leak Holley 600 cfm

Jun 27, 2007
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El Lay
Hi all, long time no post!

I have a question regarding a weird fuel leak on my Holley 600 with vac secondary.

Fuel is leaking from the primary bowl into the carb and exits through a small hole located near one of the primary venturis at the bottom of the baseplate.

I identified it after mounting the carb on a workbench and feeding gas to the bowls with a tube and funnel. (I have already rebuilt the carb and installed new needle and seats, checked and rechecked them many times. Same goes for the float level and they are not punctured or sinking either).

The manifold gets flooded in no time and I can't get the car to work unless it's full throttle (of course).

I wonder if this hole is a normal bypass or if it's missing a plug of checkball?

Someone mentioned maybe the primary valve and its gasket. They are both news and correct. What gives?
 
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What kind of pump are you running? Double check your fuel pressure- it could be overrunning your floats. Not all 600s are the same either. The main body to base plate gasket might be the wrong one. There are no check valves in a Holley carb that I know of. Also make sure that the power valve is tight too.
 
Problem now solved, but I'm not certain how I did it.

I removed and reseated the power valve once again ( probably 6 times in all since this hilarity started) and took great care in aligning everything upon reassembly. I tested the carb on the workbench for a last time, telling myself that the next step would involve buying a new carb... I filled the bowls with a funnel... no more leakage... So I put the carb on the car and it started and idled immediately, now purring like a kitten.

I have no insight to offer as to what happened. I went for a drive and the car behaves like a champ. Case closed.