Have a Holley R4779 4 barrel carb in the 66 which was just rebuilt. The pump was leaking due to stripped out screws in the bowl so I replaced the bowl. Now the carb leaks from the primary overflow and nothing I have done (replaced float, and needle) seem to work. Anyone have any ideas?

 

Replace float valves?

 

can you post a picture of where the fuel is coming out ? are you familiar with how to adjust the float level ?

 

Is the needle or float sticking open? Did you try tapping on it?

 

So the fuel is coming out of the front overflow pictured here.

 

wow !! a double pumper .. all it can be is a misadjusted or trashy or stuck float .. nothing else lets fuel in .. take the bowl back off and raise the float with your hand and see if it shuts at about a level position .. and actually blow with your mouth thru the fuel inlet and see if you can blow thru with the float up .. the big round screw with the hex screw below it is what adjusts the float level .. there will be a round screw on the left side of the carb that will be the fill level when set correctly .. fuel should trickle out of the hole when it is correctly set

 

Is the seat replaceable? Perhaps a new needle valve should have a new seat. Other than that I agree that the float just needs adjusting.

 

brain fart .. yeah the needle and seat is where the problem must be .. they are controled by the float level ...

 

So the threads the needle screws into on the bowl are stripped (so the needle would never tighten). I called the company I got it from and they are shipping out a replacement. Hopefully this will fix the problem. Thanks for all the information!