Last October I bought my '08 C50, 13k miles on it. I have a friend who's a retired motorcycle mechanic, and a couple of weeks after the purchase he came over and we spent most of a Saturday going through everything on the bike. Once we were all done, he turned to me and said, "Keep the tires pumped up and the gas tank filled, keep the battery charged, check the oil level every day and change it and the filter frequently, and ride the heck out of it. If something breaks, call me. But I warn you -- I'll probably be dead before then!"
I'm taking him at his word...
Yep that is Japanese engineering for you
. Just a few words of advice
1. If using semi synth change oil every 2500 miles or annual whichever is first
2. If using fully synth change oil every 3500-4000 or annual
3. Change oil filter with every oil change (Why not costs like $4)
4. Do valve clearances every 8000 miles or so, but generally if you can hear them clicking away you're good.
5. Be sure to clean and seal the wheels every now and then. The C50 is generally rust proof but the wheels are a weak spot. A light spray of ACF50 keeps them spotless. Also remove the headlight glass and spray and/or rust treat the bowl, they tend to get some surface rust.
6. Fit a screen, lowers and highway pegs for long distance touring. These bikes are excellent for long rides at 70+ with this set up. Just remember earplugs