Not really any unique concerns, more just general, old bike ones. As long as you stay on top of the periodic maintenance, these engines are pretty forgiving. Electrically, the connectors at the join between he frame and the front fairing see a lot of weather and are known to have corrosion issues, as well as all the connectors beneath the right side cover (battery and associated relays/connectors). Also the rear linkage bearings get overlooked a lot. The petcock on these bikes is vacuum actuated, and over time can give issues, most replace it with a Pingle or similar, but there are rebuild kits available out there as well. The stock ingnition coils can break down over time, and replacements are getting harder to find, but the COP mod has been done successfully by lots of folks and is easy and cheap to do. Everything else would be normal maintenance issues.