Any time a carb floods after it is shut off fuel has to be getting by the needle & seat. It's like the tank in the toilet. When the bowl fills up the valve shuts off. If it doesn't it run s over into the stool. Dirt in the needle & seat is the most common cause. It could be a float set too high or hanging on the side. It could be to much fuel pressure. It can be a float that is soaked up with gas or has gas leaking into the pontoon.
