I just bought myself a 1986 Yamaha exciter 570. I got it for $300 and was wondering if it was a good buy or not.by the looks of it, it has not been ridden hard.It is running and riding fine with 6500 miles on it. The track and everything else looks pretty good. This sled is pretty clean for its age it has no cracks anywhere at all and the engine is pretty clean. All of it is original. When I bought it, it came with a brand new windshield and seat cover. I am also asking how long will the engine last before I have to replace a piston or something like that?