if its the same a s the earlier gsxr and the 1200 bandit then the flywheel is not keyed onto the crankshaft and it comes loose and spins on the crankshaft sometimes, its only fitted on with a bolt on the end and the fly wheel has a taper inside it which fits tightly onto the crank .the starter gear is fitted onto the back of the flywheel and will just spin if oil has got between it and the crankshaft so you may need to remove the cflywheel and clean it with some brake clean where it fits onto the crank and then bolt it back on tight with an air gun,the other thing it could be is the starter clutch which fits onto the back of the flywheel it sometimes gets damaged and the rollers dont grab the starter gear and so it causes this same problem,ok hope that helps ...adam
adam bike doctor, June 2006