Installed these friction disks in a Kawasaki KFX 450r quad. Couldn't get the clutch to operate properly. Removed all the disks and compared them to the oem disks and found the problem. The 1st friction disk you install (oem), is narrower width wise, than any of the Rekluse friction disks. So to use the Rekluse disks, you still have to use the 1st oem friction disk, them you can use the rest of the Rekluse disks.