beardking,

You might want to check your idle mixture setting. If it's too lean, it can interfere with high-speed fuel flow. This would result in the engine shutting right down when you advance to high throttle settings.

Richen the idle mixture half a turn to a full turn, start the engine at 1/4 throttle, and see if it will advance to full. If it still cuts off very cleanly, then it's likely you have a fuel feed problem of some kind, such as the many posters have said above.