Check the plumbing from the carb to the tank. I've had the same experience with the engine dieing above full throttle once. It turned out to be the fuel filter that I bought that stated that it was for gasoline. It kept getting worse as I woked on it because the material in the filter was swelling and closing off fuel supply. I have sincestopped using inline filters and ony use the felt clunk filters like those used in chainsaws. Your problem may be anything restricting fuel supply. Try a new line with a felt filter stuck down in your gas can to eliminate the tank and plumbing in your plane.