Hallo!
I've noticed this thing during last ride: as I started the trip, Kupplung's began dragging in a soft and gradual way; after some re-starts (e.g. traffic lights, crossroads), dragging began to be more and more sudden, almost an on/off Kupplung. Engine stopped sometime too while re-starting
Do you think Kupplung plates have to be replaced? (or, at least the friction ones, leaving the plain ones as they are)
Remark: I don't know how old the plates are, they could be the same Yamaha installed in 1981 if previous owner didn't replace.
And: some time in the past I've had to unstick them because of long non-working time, worked it out simply by putting the bike on central stand, starting the engine, 5th gear in, disengaging the clutch and accelerating while braking with pedal; maybe plates are not at their 100%.
Grüßen
Simone