Needle and seat hang up on Stromberg 97

[Chris]

I have a new engine in my 34 roadster with two 97 carbs on it. It runs great...but when it sits for more then a day, when I fire it the forward carb starts pouring fuel out of the top of it (vent hole). I can tap on the top and then it is fine. I have taken the needle out and inspected it, cleaned it, ect. Still does it...anyone have any other cures? Would float level have anything to do with it? It is only the forward carb

Thanks, Chris