Hay Paul
I found a W650 a few years ago , sitting in a shed dry but dusty to the point of couldn't see what color it was.
I drove it for a year plus a summer. Spoke wheels and Carbs ... so I didn't keep it.
I really liked the idea of the shaft drive OHC system. The twin cylinder bike I have now with the cam-chain in the middle worries me somewhat. I know it's just a matter of time before the cam-chain wears out so I look at it as a short life motor.
The last "Non-Single-cylinder" engine I had (OHC-long term) was a four cylinder Kawasaki 750cc . It's chain started flopping about 50k-miles ... it did have eight valves to lift , but so does my twin I have now ???