You may need to replace the throw out rod in the clutch. If you are already at the end of adjustment, and the clutch will not disengage, that's a good indicator.
I dug out the thread I wrote up when mine broke....http://zx6r.com/mechanical-technical/50535-09-clutch-friction-plates-how-many-what-kind.html
I dug out the thread I wrote up when mine broke....http://zx6r.com/mechanical-technical/50535-09-clutch-friction-plates-how-many-what-kind.html