Bought the bike at in August 2008 at 32kkm with funky carbs; the bike wouldn't idle down properly. Brought it home and didn't touch it for a month. Surprise, it wouldn't start.
Tore the carbs apart and cleaned them that winter. Installed new float valves and O-rings and bench set up (balanced). In the spring, the bike started easily and ran like a dream. Still haven't used the gauges to balance because it runs that nice. Hey, old carbs need regular maintenance. It's not hard to do.
The 30 year old OEM suspension, rear mono shock and front springs, are crap. Advancements in bike suspensions have been amazing in the last 30 years. Rear end would rapidly bounce at ~70 kph. Some claim it seizes solid. Shops in the US can rebuild recent Honda CBR600 shock to fit ($250). Bought one and still need to install it. Monoshock linkage can squeak. Easily disassembled and lubed when installing new shock. Front springs are moosh and bottom out easily when braking. Bought Progressive springs for the front. Again, waiting on install.
The (30 yar old) ignitor boxes may (stress may) be problematic. THEY ARE FIXABLE!! Most times it's just weakened solder joints on the circuit board. Look for corrosion, resolder and you're in business. Bought a set from a wrecker that were sitting outside, for decades, and full of water. Dried them out and they work like a charm. Go figure.
Don't even worry about the cam oil issue. Many people have ridden these bikes to 125000 MILES without a problem. I bought a Dave Dodge oil mod and probably wasted my money.
The transmission occasionally jumps out of second gear into neutral. Because it is just occasional, it is not a concern. Who drives in second gear anyway? Just don't be too hard on the throttle and up near redline, in second gear. This can get worse as the bikes get more miles on them (>100kkm).
Neutral on the rear drum brake. It does its job for the 30% it actually does.