Phil, you're my kind of guy.
If you look at the normal clutch trans setup, you're correct, the flywheel/clutch is supported on a long shaft with many bearings keeping it in true alignment. The trans on the other hand, has a front input shaft that only has one bearing at the trans and the splined end is in the clutch disc.
It would be ridiculous to think that's all that holds the input shaft in alignment. When the clutch is pressed in and the disc is loose, the shaft would fly all over the place. That's why thy have a pilot bearing located in the end of the crankshaft.
This is exactly what you've done with the bushing in the motor side case and the pilot on the clutch side. I often wondered if this would be an issue as it does just kind of stick "out there" without any other support.
I know that you've proven your theory and what you have now works, but I would be leery of the bushing wearing out and getting loose. I know that you've got an oiling system incorporated, but I would think your next and final step would be to make the pilot as small in diameter as you can and still room done on the motor end for the crank nut etc.
Once you get to a small enough diameter, I believe you should be able to source a pre-lubed and sealed roller or needle bearing that the pilot rides in.
I'm not sure is your pilot is aluminum or steel. If aluminum, my fears would be that it would wear quite quickly do to the shock pulses on the motor and the high frequency oscillations back and forth in the cush drive urethane blocks.
I've read the entire thread, but over this long of time I'm not certain how many M3W's have the slipping sensation that still have the old Harley compensator installed.
In the Harley type compensators, they have the BMW rubber flex that bolts to the clutch/flywheel shaft and then to the housing that incorporates the Harley compensator. The motor end of this is also supported radially through the compensator so there is NO end wobble and the clutch/flywheel shaft stays a lot more stable than with the Centa just sticking out there...
I applaud your effort and resourcefulness!!!
Great work.
I know you mentioned the chain size, but are you running an O-Ring type chain? I've been running an o-ring chain on my old Harley for 12 years and after the first adjustment, I've not had to do a thing to it adjustment wise. I do on occasion spray and wipe it down with WD-40, but that's usually just once a year.
Keep the tips coming and drive safely.
