I'm using a 750 vacuum secondary carb on my car and from the beginning it has always taken just 1/2 pump and it fires immediately. Lately I have had to pump the crap out of it to get it going and it has had a bad hesitation off idle. Since Holley uses an external accelerator pump, when they go bad they normally leak on the intake manifold but mine wasn't leaking. When I took it apart I found that the little strap that holds the check ball in the fuel bowl had come out and the check ball was just floating around in there, so whenever I pumped the throttle it was just pushing the fuel back up into the fuel bowl and not through the accelerator pump circuit. It was an easy fix and now it's fine. I've never had this happen before in all my years of using Holley carburetors but I just thought I'd pass this on in case anyone else ever experiences this symtom.
