I know you said it doesnt rev high before cutting out and i assume it starts up again without a problem so before you get into changing coils and modules again try isolating the cutoff wires in the carb and see what happens. if it still persists check your float level(sometimes the shorter needles help, or just file about 1/2mm off your existing one). Another stubborn problem is sometimes the fuel cap is not venting properly(loosen it up and try again).
