hey, my son got a used kx125 from his mom for xmas, does anyone know how I can find out just what year it is? We think that it is a 1994 but we are not sure. the rear sprocket has 50 teeth , but when ordering parts it shows that 50 teeth came in 1996, 1994 shows 49 teeth, does anyone know how I can find this out or can you just get however many teeth for any year... thanks...