Hell all,
I have re-adjusted the gap between engine body and the clutch to be 5mm (thanks to a hex key which I used to enforce this gap while tightening the screws) and it seems that the scraping noise has disappeared. The clutch is working though there's a very slight slippage which I think is acceptable. I'll see how it goes next time I used it but I think it's in a much better state.
I'll keep an eye on the cork as you have suggested and will inspect next time I disassembled the clutch body. Would you know what is the thickness of a brand new cork ?
Other than this I'm happy to move on and thank you very much for all your help on this topic. I wish I can find a forum as good as this for home appliances.
