Wcfb checkball qeustion

If you put fuel in manually the pump will work. Fill just the bowl and keep pumping and I am sure you will run the pump circuit dry unless you refill the pump area. You could be pulling the pump up to far and fuel is coming in the side. I have seen this in the past. Put the carb body in the oven upside down heat to 250 and it should fall out.If not use air and reverse the flow blowing it out while hot. Let cool then take a small counter sink bit and reface the seat by hand and install a slightly larger ball. If you need a larger ball measure yours and I have them. price of a stamp