Sounds like MAYBE the seat needs to be polished up a little better. Just an over the interweb guess. I do know that if these carbs aren't THROUGHLY clean they will cause you trouble. Float level isn't adjustable so that rules that out. You bought a new needle so that rules that out. So if it is flooded after sitting, then fuel must be getting past the needle and seat. When they work right they are a pretty good little carb.