Here's a weird clutch problem...
S&S 88"EVO
Baker 6OD trans
Rivera Primo clutch (don't know which model...no visible markings and no documentation with bike...the friction plates are blue). I'm assuming it's one of the 'Pro' models.
On a recent trip I travelled over and back on a mountain pass. On the return trip, while stopped at a light, I grabbed the clutch lever to go, and it went completely slack. No tension at all.
Thinking that somehow it must be the cable, I replaced it. The ball and ramp ***'y looks nearly new, and the spring has good tension. Throwout bearing/washers and shaft are new-looking as well, and there is no sign of damage to the push rod or the jam nut.
I adjusted the cable air gap to 3/32". When I started the bike, the bendix gear kept missing the sweet spot. When I did get the engine warmed up I pulled in the clutch lever and the motor stalled. Several repeats of this indicated that the clutch was causing the engine to load and stall.
In addition, after start-up the clutch cable developed nearly 1/4" of extra air gap!?
Re-adjusted the clutch push rod. Re-(grind, grind)-started the engine. Same same. Engaging the clutch killed the engine.
Did not do anything to clutch ***'y or hub.
Have done due diligence trying to find an earlier posting, but no luck.
Any thoughts out there???

 

You say the pinion gear misses the ring gear sweet spot...

Clutch hub nut loose?

 

Or bearing going/gone?
Shouldn't be a "sweet spot" on starter engagement. If you have one, you have a problem.

 

Tight nuts (hey, it's cold!) but methinks you may be right about the bearing.

By 'sweet spot' I just meant that the pinion gear and ring gear teeth weren't in alignment. This happens once in a while, but not enough to consider it a serious problem until now.

Time to pull the primary cover and start messing around again. Dang!

I think this year I've spent nearly as much time wrenching as riding.

 

Tore into the clutch pack last night. All the plates and friction disks look nearly new. There is a significant wobble (about 1/8" of play) when I move the hub up/down/side-to-side. Also the primary belt is riding about 3/8" away from the outer flange of the hub.

Found lots of metal shavings laying in the bottom of the primary case, but no noticeable damage to pinion or ring gear, because...the grinding noise was NOT the pinion gear, but rather the outer rim of the hub rubbing against the primary cover. Yikes!

As you've probably guessed, I'm a newbie with big twin clutches, but am muddling along, figuring it out as I go.

All input is greatly appreciated!!!

 

Definitely the hub nut. Cinched it down as far as I could w/o the tool, and the hub moved inboard a good 1/4".

It appears that whoever messed with this last (not me, folks!) used never-sneeze instead of loctite on the nut. And probably didn't torque it either.

Had to clean up a bit, but other than a little metal removal, everything looks ok. Waiting for the tool to arrive, then back together it goes.

Now I know a little more about clutches.

And next time I'll dig in a little farther before posting.

Thanks for all your input.