Here is the picture I told you I'd send.
From the PM I sent.....
The clutch pad holder is bolted on the (hollow) clutch shaft (goes through the case). There is a woodruff key that keeps the clutch pad holder in place..you may of stripped the key. There is a smaller shaft that the bucking bar moves so when the clutch is disengaged the flywheel separates from the clutch pads. The small gear also has a key, of course it may also be the one stripped. And you have a key on the chain sprocket. In the meantime, I'll see if I can drag up a photo.
Ron
Personally...unless you have a pull start, I can't figure out how you can start the engine and it will not pull. If you have a broken key, it shouldn't start.