i am currently rebuilding a bike for a friend. it looks like a 91 cr 125r which is what i rode but not quite. it is all orange with mono shock and a drum rear brake. mine has mono with disc rear brake does anyone know how to tell what year it is by the vin#? i'm guessing 89-91 but i need to know exactly what year. i know a lot about bikes but this has me stumped. any help would be appreciated.