Hi FilthyPlumber,
Not much changed over the years except the carb needle with less clip positions.
They're a solid bike to start with and have proven old school technology.
See that your jetting has been changed which needle are you using?
As far as lubing goes use a good quality oil and change when appropriate.
Use a waterproof grease on head bearings, swingarm and linkage. They are often undergreased from the factory and not waterproof.
Part numbers change often with bikes, it still maybe the same part but from a different supplier or when superceded or small change is made. Check the Yeltrik site for part numbers.
http://partsfinder.onlinemicrofiche.com ... finder.htm