Not a bad machine compared to others in it's generation. First thing I would do would be to junk the rear suspension, unless you don't plan on riding any trails. M-10, or used Extra-10, depending on your budget, would be the suspensions of choice. Engine has plenty of muscle as is, will not stand up to current gen. machines though. Still plenty fast enough. Can't think of any known issues, they were pretty good sleds. Should last your buddy a long time.
AL