[gunnyman]

It could possibly be the fuel pickup tube in the tank being clogged.First I would jury rig a gravity flow tank in front of the tank and see if it would prime and continue to operate. If so it is your tank pickup clogged. As a precaution check your fuel water seperator. Is it filled? Or is it drained wahen the engine quits? As to priming I found that a squeeze bulb like used on an outboard fuel system will allow you to prime the engine with ease. Hope this helps.