Silly advice, but, when I got my '84 KRS, 83K miles, reasonably well cared for, some dealer maintenance records, which didn't seem correct?, third owner, the seller was not forthcoming to simple questions, so low ball/ haggle. Many of us have these early nice cam bikes. The seller asked what I was gonna do with bike? I said, "Take it apart!" Rode it home, rode it for inspection, then take it apart. Leaking FD, leaking forks, useless front brakes, leaking rear MC, cracked right bag, no leaks engine/tranny, tank was very good, original fuel pump, hoses and carrier, and on and on and on. Original throttle bodies updated, front end up dated, new this new that, and that and that. Work a little each day/night. No rush, do it right, forget the cost.
No fiddle faddle around, spray this, scrape that, take it apart. But before, read every fricken frakken thing available on the bike. From every period bike mag review to every available repair manual, to every inner web article, every night, read, learn from others' many times mistakes/triumphs. So I knew wth I was doing. Clean everything as you go. Three years later still gonna do some stuff this winter. That's my story FWIW on an early K bike.
Oh, the crankcase Z hose vent. One of first things replaced even though it looked OK. How does it run today? Compared to an airhead? Like a scalded cat.
