Buddy of mine just picked up a 99 RM250. It's a real nice 1 owner machine. It was bought and used as a play bike. It's all stock and runs good. Only problem is the clutch is kinda grabby as you let it out. What causes that? bad clutch? wrong oil?
Try changing the oil. I have a 99 RM250 also and as soon as I picked it up the clutch was grabby, replaced the oil and its fine now. I always run ATF type F, cheap and works like the best of them, can get it at any auto store. If that doesn;t work, he can try to sand the plates lightly and it may solve the problem also, that worked on my 96 RM250.