Given the limited info available without actually HEARING the noise first hand, I might be inclined to suspect the dampener on the primary drive ! Its job is to smooth out the intense power pulses of the V2K engine & then pass the power on via a chain similar to a automotive timing chain , to the trans.
Just my logic, but if the noise sounds "internal" , I am betting on the primary drive system. It all located behind the leftside engine case chromecover.
This doeesnt necessarily mean that there is an actual problem within it, but it could be the source of an" audible reaction" to a clutch issue as well.
I was wondering if there was some kind of tensioner , etc. with the primary drive. That would also explain a slight driveline lash that I had noticed recently. I guess I'll pop the cover and see what I find.
I still can not determine where it is coming from or what it is. It seems to have disappeared for a while, but now it is back. Definitely not rear hub bearings or output shaft problem.
You're probably right, I just want to be clear, though.
When my rear hub went, it made an occasional lightish "thunk"ing sound, not the grinding you'd expect to hear from a failing bearing. A quick lift on the hoist and a few spins of the rear wheel and I knew it was from the rear axle area, probably the bearing since this was a known issue and my bike had right around 15K miles on it. When I took it to the shop, the bearing came out in pieces. Luckily I had the parts pre-ordered.
My biggest fear is when I die, my wife will sell all my guitars for what I told her I paid for them.