I have a 2006 kfx 80 i pressurized gas tank with air after removing line and no gas was coming out. I then found out that it works off vacuum after re-installing hose i found extreme amounts of raw gas on top of piston? When i install spark plug raw fuel comes out of exhaust @ least 1/2 cup every revolution? Also there is a rubber drain plug on the throttle side of Quad on the bottom below the head when i remove after sitting overnight all the gas in tank will be there and drain out? i removed fuel valve and inspected diaphram all ok. also i removed and inspected carb all looked ok. PLEASE HELP!