Second brand new Holley carb flooding?

Gwywnc said

Hi thanks for the replays. This is the third new carb. The first new carb was a 670 Holley street avenger. It worked great and never flooded. The problem was that it stumbled at take off and I couldn't get it to stop so I sent it back and got the 750 double pump. Both the 750s that have flooded seem to have started it after letting off the gas and the motor winding down. The gas is coming out of the front lil tube that sticks up. I adjusted the float level and looked at the needle of the first 750 and it didn't help. The only reason I went with Holley is that say these things are tested before shipped and ready to bolt on at go. If I can't get get figured out I will never buy another Holley.

Click to expand...

Could have just put a larger squirter in the first carb and adjusted your accelerator pump to eliminate the stumble. Reason it was doing that was because your motor was leaning out between the idle circuit and the main jetting taking over...

If you are doing any drag racing you might want connect the primary bowl vent tube and the secondary vent tube with a piece of rubber hose with an oval cut out of the top of the arch. Prevents fuel from sloshing out of the primary vent into the carburetor when the car launches.

After you get your problems ironed out that is...

Probable causes:
1.) Contamination in fuel system
2.) Float level is too high

3.) Fuel pressure is too high - kinda wonder if its this considering your first one didn't puke fuel out of the vent... Still a possibility, but need to know what pump / psi you have

Give us some more information so we can better assist:
Fuel Pump - part number
Filter - what is it and where is it located
Fuel pressure - if you have a gauge installed?
Regulator