I have a mildly built 350 with a 600cfm holley on it, and when I punch the gas from idle it stumbles then takes off. I don't think it's running rich because all of the plugs look good, and it runs fine before and just after i hit the gas. Is there anything I can do to fix this? I don't know alot about carburetors so I'm looking for some help. Thanks.

 

does it only happen off the line? Might be a fuel filter.

 

Fuel filter maybe...........Also pull the sight plug from the side of the bowl and check your fuel level. The needle and seat may need adjusting. I have seen carbed cars actually slosh the fuel from the front bowl backwards and come out of the airhorns!This usually happens during launches

 

What's the list number of the carb?

Sounds like a lean stumble. When you punch it, you're opening the butterlies quickly. To compensate for the huge rush of air, the carb uses squirters to spray more fuel into the engine.

There's 2 things you can do. Buy a pump cam kit to try different cams so that it can adjust the timing of how much fuel is injected. The other thing is to change the squirters. You probably have 25's. Install some 31's so it will inject more fuel from the accellerator pump. If it already has 31's, install a 37.

That should fix your stumble.

 

I agree w/both of these fella's. prolly the fuel level. if its a vacuum sec. carb., then maybe the sec. are opening too rapidly?

chris

 

Not sure on the number but it is a vac. secondary with manual choke. I've already check the secondaries and they don't open till it hits about 4500.

 

The list number is on the choke horn