I have done everything possible but still have poor fuel flow. Changed filters many times, drained fuel tank and blew it out with air. Added fuel treatment for bacteria and yet it runs smoothly for 1 to 2 hours then quits. After setting for 15 to 30 minutes it starts and runs fine. I have considered the possibility that something like a piece of paper or plastic is floating in the tank but no easy way to confirm it. Removing the tank is a huge job but I am not sure what else to do. Thanks in advance for your help. Ed