Trophy New Noise

After 8,000 miles since May on my 1993 900 Trophy, went shopping today and a strange whine started with some vibration, nothing from clutch side but alternator a bit vibey.
It's due for an air-cleaner service so off with everything including carbs and remove alternator to find the drive vane pulley has stripped its spline and broken the attachment bolt.
The splines on the shaft look serviceable so I have ordered a new vane pulley and bolt, should be back on the road by the weekend.
Glad it didn't happen while I was in Albania in June or Norway in July where I saw 99,999.9 miles on the clock.
Anyone else had this failure?