I think i need stem bearings but am not sure. The 82 is my first bike so I do t have much experience to compare what I'm feeling in the bars. It feels a bit stiff and there a noticeable "give" on the tension when centering the bars. Is that normal?
A stock Vision has ball bearings in the stem.
The centering effect you describe can be caused by dried grease (easy fix) or dimpling of the bearing races.
If you do have to replace the bearings, there are tapered roller kits available:
https://www.ebay.com/itm/Yamaha-XZ550-Vision-1982-1984-Steering-Head-Stem-Bearings-Kit/233199208479?epid=26027336364&hash=item364bc1881f:g:uDUAAOSwA71dSNYq
As old as the bike is, although mileage has the most to do with it, I would just about bet on needing new bearings and races. Replacing them was always on the list whenever a new steed joined the herd. It was always something that would need doing so I just got it out of the way.
I am in total agreement with replacing the original loose balls and races with a set of tapered roller bearings. The roller bearings will take a lot more abuse and not show it compared to the loose balls and races, and they provide much better stability.
https://www.allballsracing.com/22-1015.html
+1
Replace 'em.