I have a 2000 King Quad 300 4x4. Gas is not flowing from the shutoff valve to the carb. The last time i had it cranked, I wanted to let the gas run out of the carb so I left it running for an additional minute or two. It would not stop running. I let it run for about 5 minutes and then just turned it off. After that it would not crank. I took the hose off the line coming out of the shutoff valve and gas would not flow at all. I took the shut off valve off and blew it out real good with air. I noticed it had an additional line coming from I think is the fuel filter or pump. Any ideas of what the problem would be? Thanks.