ATC90 Clutch slipping at high RPM's

[jeddy]

I have a 1977 ATC90 and the clutch is slipping at high RPM's. I've adjusted the clutch (turn in bolt until resistance is felt, then 1/8 turn back and lock down with nut), but it still slips. I'm pretty unfamiliar with these clutches (I normally ride a 350X), and the manual from the Library is checked out. Any help would be appreciated, I'm trying to order parts, but I'm not quite sure what I need or should check. Thanks,
-Jed

[team-red-rider]

theres not really a clutch onmine the primary drv gear was broken and caused a slipping problem