serious carb issues

The idle screws on Holleys only meter fuel. If things are tuned and the carb is sized right, the engine will die simply by turning the mixture screws all the way in. If it continues to run (4 corner idling) the float level may be a little high, the secondary plates may be open too far, or the power valve(s) may be opening, or a gasket leaking, the ide speed may be too high.... In primary circuit idling (no secondary screws) the secondary does flow a tiny amount of fuel at idle but it shouldnt be enough to run the engine.