Right then. I looked at the clutch yesterday. I managed to get the clutch plates out – the plates with friction corks were all covered in a hardened dirty crud. There is very little wear on the corks and it looks like most of the clutch plates were not doing much as the clutch plate tongues were such a tight fit in the casing due to the crude build up. Also the 3 thrust pins were not pressing evenly and so they are now not the same length.
So I will replace the clutch plates with new ones clean everything up so they move freely. Fettle the thrust pins so they do their job properly. Replace magneto chain and drive chain as they were both worn.
What should I do about the cork friction pads which go through both sides of the clutch sprocket, they are covered in the same crud as everything else so it would be silly not to replace these when changing the rest. Is it possible to have modern material bonded to it? If so who can do it and what spec should it be?
By the way to get the clutch sprocket out I had to undo the gearbox to allow it to be slightly raised as the sprocket wouldn’t clear the base tray. One good thing the roller bearings stayed in place.
Help and advice appreciated.