Reply to edb:
as Neil said, there is a very fine distance of one pin hole either way of being correct for the clutch to engage or not especially when the clutch fingers get worn and flat spotted.
If you turned the adjuster several holes clockwise or it was that way when you got it you now need to keep backing off the adjusting collar--suggest adjust it out to loosen the clutch engagement position so it does not lock over and advance until you get the resistance/lock over needed.
IF the clutch is adjusted too far in it will not lock over either just as you describe.
Either this or Neil's method will get you there.
Cheers,
Eddie B.
Go with Eddie's approach! : ) I forgot to take into account that you said it turns the main over when held in. That indicates that the clutch is definitely making sufficient clamping force, so if it doesn't over-center, then it's probably too far in, so work your way out, one notch at a time. I found after adjusting my clutch post-reassembly, I had to adjust it a couple of times as it "bedded" in, so you might find this too. One way to check if it's too slack is if you leave the compression engaged, and try to engage the clutch, if it makes a poor half-hearted attempt at turning the main, you might need to tighten it up a bit, even if it over-centers ok