Why is my Kawasaki ZXR750 clutch slipping?

Q. I’ve just put some new clutch plates in my Kawasaki ZXR750 H2, but it’s still slipping. Can I adjust it out?
wingy46, MCN forums
 
A. As your clutch is hydraulic, the only adjustment is at the lever forhand span using the small, four-position chrome wheel on the top of the lever, one being the farthest out and four being closest in.

If the clutch plates have been wearing out over a long period of time, and you (or someone) have been topping up the clutch master cylinder, there could be too much hydraulic fluid in the reservoir, lifting the clutch slightly.

It’s best to re-bleed the whole system with new fluid and allow an air gap (as required) at the top of the master cylinder reservoir to prevent hydraulic locking.

If it isn’t this then it could also be the slave cylinder piston starting to seize due to poor maintenance or age? That would then need stripping, cleaning and probably new rubber hydraulic seals.