Looks fine to me. If that slide is that closed and it is revving up then you HAVE TO HAVE a air leak somewhere. Make sure you carb is all the way down. Make sure the cap on the side of your carb in not cracked and make sure the backing plate on the motor is not coming loose. Those are all the places that can suck air into the motor like if the carb was open that I know of. Hopefully someone else chimes in here with a different idea. Should not be a bad motor.