these bikes suffer from a common clutch problem which is the clutch pressure plate wearing and the ball bearings in it break up,it looks like a u.f.o and is bolted to the outside of the clutch with about 8 bolts with 5mm hex heads on them.you will need to replace it is this is the problem you will usually see damage to the centre of the pressure plate if its the problem.
adam bike doctor(of milton keynes motorcycle centre), January 2011