Clutch discs with 24,000 miles are likely worn out, especially if a lot of those miles were in the city or on short trips, where the clutch was being used a lot. Clutch wear does not happen when the clutch in engaged most of the time, like long trips. But wear happens every single time you use the clutch. I had a Kawasaki that required new friction plates in under 20,000 miles, because they were warped, causing the clutch to not completely disengage. Definitely get some new friction plates in there, and while you have it apart, sand down both sides of the metal plates. Clutch plates are just like brake pads and shoes. They wear out with use.