So we finally got around to removing all the emissions crap off Rosie's WRR...
It's heaps lighter now but seems a bit down on power
Actually, the engine was out for a full teardown to replace this:
2008 with 30 something thousand km on the bike. The gearbox countershaft output bearing had suddenly spat all it's balls out resulting in lots of nasty noises & loss of drive. Luckily there was no other damage. Still a big job to pull the engine down almost completely to get at the damn thing, would be horrifically expensive if you had to have a shop do it. All the rest of the motor insides looked pretty good, valve clearances ok, ring gaps well in spec, clutch good etc etc.
A look around the internets doesn't bring up any signs this is a common problem, my guess is that it had been literally 'ridden hard & put away wet' by the PO & corrosion from a drop of water in the bearing was the root cause. Rolling element forensics experts feel free to comment