Are you looking to switch from the stock ones to bronze or roller bearing?
Bronze will be the cheapest. Thats what I'm doing. Roller bearing would be best I'm sure but more costly. You can buy a kit for doing the roller bearing but I'm sure you could source everything yourself cheaper.
Bronze should do the trick just keep the grease on them.
Shaun
Just put a set in my 80 and fit fine just make sure you get the tube as well. Some won't work with the stock yamaha one. All from mikes
Good words to live by