[Cam]

Sounds to me like one of your fuel hoses is collapsing (somewhere before the bulb). This has been a big problem with the ethanol gas. The old fuel lines cant't handle the new gas and tend to break down inside the hoses. Had the same problem, different engine, and changing to new hoses solved the problem. If you didn't say you ran it off a seperate tank, I would have told you that something in the tank is blocking the pickup.