I have a Holley 750 double pumper with mechanical secondaries and manual choke on a 383. I can't stop it from overflowing with gas, Iv'e adjusted the floats a number of times so I'm pretty sure there right, Also this carb. is fairly new and looks to be in good cond. I am running 6 to 6.5 psi on the fuel, Is this to much for this carburetor?

 

Are you adjusting it while running or dry/bowl removed. I would suspect the float needle is damaged or the float is bad.

 

I set the floats dry started it up and fuel started coming out the vent, So I backed off the set screw and turned the float adjustment clockwise 1/2 turn. The fuel still comes out the vent. I assumed that the pressure was to high at 6 to 6.5 lb.

 

k -

6 - 6.5 psi is normal. You are checking the pressure right before the carb, right?

Sounds like you don't have enough travel on the adjustment screw, but that's pretty rare.

Archer

 

Make sure needles and seats are clean .

 

https://www.bing.com/videos/search?q=adjusting+the+holley+float+levels+on+a+75 0&view=detail&mid=D3D3BE4069BEFA25772AD3D3BE4069BE FA25772A&FORM=VIRE
This Might help..

 

I found the problem, It was the O ring on the needle and seat assembly. Thanks for all the help!

 

Awesome