01 sportsman 500 h.o. carb issues

[jak2000]

i got a weird one for ya when i fill up on fuel under hard acceleration or going up a steep incline it acts as if its starving its self for fuel or almost like its flooding its self out tried everything i can think of i have replaced all the fuel lines cleaned carb/fuel pump and also cleaned the tank and nothing helps???????????????? totally stumped on this one

 

[Garryese]

If you are saying it is worse when the tank is full of fuel, the fuel tank vent is plugged or pinched off. The vent line is very small and runs from the top of the tank and loops at the top of the steering stem.