The problem your having in fueling your boat is caused by a small spring loaded flapper valve located in the bottom of the filler tube on your fuel tank. this valve is meant to prevent fuel vapors from escaping while the fill cap is removed.It is similar to the flapper in the fuel tank of your car, which is depressed easily by the fuel nozzle when you fill up. But on your boat, because it is located about 8" deep in the filler tube, the fuel nozzle can't reach it to push it out of the way. There is just enough resistance to cause fuel to kick back and stop the pump. Take a flashlight and look inside tank filler neck and you"ll see it. It seems to be just another useless EPA device, so I can't really tell you how to fix it but lets just say, mine take fuel just fine now! And PLEASE, FLASHLIGHTS ONLY to look inside.