I'm considering purchasing an early 90's K100RS that looks to be in really good condition. Long ago I had a K75s, so I know enough to know I really like those K bikes. But I was too young and dumb to fully appreciate the bike then, or learn much about it. Now that these bikes have been on the road for two decades, I'm sure there are people out there who know a lot about them. What are the things I should pay special attention to? What are the weak links on these bikes?