On my "new" 97 K1100lt I noticed there is a scraping noise when backing up. I put a jack under it to get the front wheel off the ground so I could spin it backwards to see if I could hear the noise. It seems to be coming from the right side disk. It has floating disks, is this something normal for the K1100's? The pads have plenty of life left in them.

Check the state of the disk, has it got any ridges? I think it may just need the callipers serviced. If the backing plate on a pad has moved it could be catching the disk as it rotates.

While you're down there is doesn't hurt to double check that the wire for the ABS sensor isn't rubbing against the tire. DAMHIK

Check that the anti-rattle clip is there (it's a small bar that goes across the centre of the brake pads and is held in by a spring clip that itself is held by the main pad pins). If that's missing the brakes make all sorts of funny noises. As Duck says, DAMHIK. Also, it doesn't hurt to remove the brake pads and scrape the crud out of the calipers with a wire brush. Remove the dust seals first because if you don't, the wire brush will. Before you replace them, make sure that all the dirt has been removed from around the pistons. If the backing plate on the pads is rusty but the pads are otherwise in good condition, apply a file/wet'n'dry/rotary brush as required.

Ok. Thanks guys. Now that I know it's not normal I'll check it out.

It maybe just dust. Sometimes just cleaning the disc helps,  including the slots in the disc. Sometimes cleaning the discs and pads helps.