A buddy of mine has an excell 4 that I work on for him. Problem is he rolled it, and now it syphons fuel out of the carb overflows. He had the carbs all apart, and the float and needle/seat are fine. I am wondering if it is the diaphram in the pum is stuck allowing the fuel to flow by. Any sugggestions, he is a good customer, and I need to get this fixed. Maxdlx