I gave it a try.Unfortunatley due my own stupidity it didn't work as i assembled the starter clutch wrongly - i put the new spring in (which i took btw from my LC4's old fork seal as i've changed them to new ones) and it fit just perfect.
Then i tried to install the metal _??stopper ring??_ and i think, i did it wrong.
After putting all the things back together in the engine i gave it a spin.
Oh the horrible voices and inhumanity.
Worst thing was, i had to go to Germany the next day on that bike and it was evening already.
So i opened up the engine again and discovered not so good news.
The metal stopper ring came off and spring was cut in pieces and the little knuckles ing the s-clutch were all over the place.Fortunaltey none of them did not fall deeper into the engine.Then the cleaning began.After that, when i got all the pieces out, i re-assembled the s-clutch but it was ruined by the starter mechanism and starter sprockets.
"Ones misfortune is another's happiness" as they say - I remembered, that there's a guy i know, who had blown his 620 LC4 Duke engine block.Here the distances are small, and he was about 60 miles away and he had that s-clutch he was willing to give away.After 3 hours or so we were back at the garage with decent part.Quick install, quick test - all good - then quick oil change to wash away the rest of the blown spring and other metal pieces from the block.
So, i think if i had assembled all of the pieces correctly, it would work.
Old spring was quite a snake already if to be honest.
But still, thanks a lot, Losiu