you dont have to pump it up so hard that the float leaks! the idea is just to pump all the air out so you get a good siphon effect. just pump it up till its firm, and make sure the vent is open on your fuel tank. if your still havin problems out of it, make sure all your fuel lines are secure and leak free, and also check that your fuel pump isnt leaking cause you may have damaged the gaskets while takin out your aggression on the siphon bulb! best of luck!!