A 1990 PC800? Wow!. :grin2:
I bought a leftover 96' new in 1998 for $6000 out the door and loved it!
Things to look for:
The stator is a when, not if replacement on higher mile, pre-mid 1994 PCs. A new part # after meant they fixed that.
Also, the clutch springs aren't the strongest.
Come plate replacement time, it's a worthy upgrade.
If you smell gas occasionally, the automatic fuel cutoff diaphragm is likely leaking. It lives just ahead of the fuel door up under that top cover. Find a cheap rebuild kit for a CB650(?) petcock, swap in the diaphragm and new spring - problem solved.
General stuff? It responds really well to a set of Progressive fork springs, shocks and maybe raising the forks 10mm in the clamps - all relatively inexpensive changes.