I think I'm the only one here with an 850 LS.
The bike needed lotsa love when I took it in. It ran rough and looked worse, but it did run. It's got 60K on the clock best I can figure out - incomplete records, so don't really know for sure. It's had head work, but I don't know what specifically, but it's got dual valve springs and the ports were modified because the 32mm Bings don't fit like they should. It's got 34mm flat slide Mikunis, and that's how I got it.
The bike definitely was loved in the past, but started using oil and interest waned (my guess - though it was using oil) and wound up in the hands of an unscrupulous college student who accelerated the downward spiral, among other things, dumped it in a construction zone hotrodding in the city.
After all that, it still ran. It had been running rich and the left side was so carboned up, it made a knocking or ringing sound with the valves hitting the piston. Replaced the rings, cleaned up the heads, repaired the broken fins, replaced the 2 into 1 with stock exhaust, straightened the wheels, replaced the mirrors, fixed the levers, recovered the seat, replaced the black plastic fairing piece... and that's just the main stuff.
It is waiting the removal of the left side again because it sounds like I've got wrist pin noise - logical due to the strain with the earlier carbon build up. But it runs great with loads of power. Its personality isn't like my other bikes - it WANTS to go! I find it difficult taking it easy on that one.
One thing I know I'll have to do is put some attention on the breather. The R65s don't have the same breather set up as the larger bikes, and I think it's not really up to the increased capacity. Besides that, my hose out of the breather needs replacing and makes a mess in the starter area.
I've heard that the R100 cylinders don't work very well since the push rod tubes are at a different angle, so don't seal up that well. It would be nice to have nikasil cylinders, but don't think it's in the cards.