Hi Mog 37
I have considerable experience of a similar issue.
This is highly likely to be your clutch slave cylinder starting to give up. The issue you mention happened twice to me both times the slave cylinder was U/S and a third time it was the clutch master cylinder. Another option that others have experienced is a broken clutch spring or even a broken pressure plate. No way can I envisage the drive roller rubbers being involved here.
I do considerable miles in our M3W and any of the issues mentioned are engine out to solve.
Good Luck
Ian Parkinson
Morgan Three-Wheeler Touring Group
