Honda 350 4trx leaking from drainage hose (overflow)

[kielly32]

I have a 1992 Honda 350 Fourtrax and a week ago my fuel pump went so i hooked up a lawnmower gastank with a valve and a hose leading to the carb (its on the front rack) and just yesturday she was leaking bad from the overflow even with the bike off. valve is only turned 3 times adn if you turn it 2wise it wont get gas. Its not my jets that are up becasue the bike would spit and sputter and have no power as it happened to me before. So what could it be????