And its not a stock a stock cag engine. It what a beleive is a 47cc. With a big bore. I drilled a hole in the intake and tapd for bb and ported out j7st the intake and gasket. Made it a real smooth transition to the boost bottle with it pointed toward the motor as much as i could. Got 7 tooth front and havent counted but think it was 52 or 54 in rear. No take off but pulls hard after about 20.