I have a 15.5 HP Kohler Command in my craftsman, and it is fluctuating between running great, and not running at all. It can run great one time, i shut it off, and let it sit for 15 minutes, start it up, and it wont handle any throttle without dying. i have a clean tank, a clean filter, clean carb, clean fuel, and a good float and needle + seat. The only thing that i can think of is that i removed the rear tank and put on a tank in the front, so it gravity feeds into a fuel pump. could the factory kohler fuel pump be force feeding my carb?