Hey guys, having pretty much the same problem on my 94 YZ 125. I bought the bike used and ended up doing a total bottom end and top end rebuild before I ever got a chance to fire it up. About the only thing that I didn't replace is the clutch setup. I used a set of digital calipers to make sure that the clutch springs, steel plates, and friction plates were all within spec, as they were. I installed a new Motion Pro clutch cable and MSR clutch lever, and tightened the cable adjustment up before starting the bike for the first time.
Once I got the bike running I noticed that the clutch wasn't operating. I have torn cutch-side of the motor down several times and can't quite figure out the problem. There's no shoulder on the inner clutch hub to show any signs of wear there. The bike already had a Hinson "Billet Proof" clutch basket, whch looks to be in good condition. It's still using the stock inner hub and pressure plate, but everything looks to be good on those.
After tearing the clutch down and putting it back together several times now I still get the same problem. I haven't even tried starting the bike since the first time I experienced the problems, but with the engine off, transmission in gear, and clutch level pulled in the bike still will not freely roll back and forth.
This is my first time dealing with a dirtbike motor (have tons of automobile engine experience), and I just can't figure this out. I've tried manually rotating the clutch lever (the one attached to the engine side cover) and it will go a tad further than the clutch lever will pull it, but even with that lower lever bottoms out at his furthest position the bike still doesn't want to roll freely. I'm scared to start the thing up, put it in gear, and dropped the bike and get hurt lol.
The one thing I've noticed is that when bolting the pressure plate up it doesn't get any tighter against the clutch/friction plates than when it's just gently resting against the plates, unbolted. Is the pressure plate supposed to sinch down on the plates a little more when you bolt it down? Or is it normal?
Any ideas/help here would be very greatly appreciated!!