I have a two barrel holley on my supercharged 1500cc pushrod 4cyl. I've been trying to get it to go properly. It seems that it's syphoning fuel from the accelerator pump discharge nozzles. Why would it do that? It has a wee needle type thing, and the other carb I looked at had the same thing. My book showed a ball and weight, but with a ball in place the retaining screw wont go back in. I'd presume that they would run one or the other. (A ball and weight, or a needle)
I've had to put in BIG jets to get the bugger to run. I have the powervalve removed, and plugged up. If I externally reference the powervalve, it will cause it to richen up too much for such a small motor as mine.