Quoting what Wade said and I strongly agree with him:
"Cars or bikes, I won't buy anything that has been "chipped," "tuned," modified, "Stage III", dyno-tuned, etc. Too often it has been done wrong and the engine has been run rich or lean for thousands of miles." I could elaborate on this but just picture ol' Bubba, tuning his bike from a magazine article, while he drinks his Beer and munches on some Pork rinds
Use your head and inspect the bike from top to bottom--look underneath the engine for any damage or leaks. While you are laying on the ground, look for evidence of a fall/ slide out, which will be apparent on the bottom of footpegs, frame, center stand and the exhaust system. Do the front fork seals leak? It's common on some older bikes.
Obviously, ask about maintenance intervals. Here's a big one: Have the valves been adjusted? Have the seller prove it by a dealer repair order. Some will say that they did them their selves, so take a magnifying glass and look at the bolt heads on the 'Valve covers,' and you can readily see if a wrench has ever been used on them. I bring this up because a valve adjustment if you can't do it yourself can cost from $100 to much, much higher.
If the chain is clean and the rear sprocket in in good condition, the bike is clean, runs well without you having to repair something for it to do so, then you are probably okay.
By the way, I have known of little 50cc Honda step Cubs that were like new at 40,000 miles and a friend had a 1976 Yamaha XT500 Dualsport that had 65,000 miles on it and only had to have a few plugs, tires and chain/ sprockets. There isn't a bike out there that shouldn't easily go way past the 100,000 mile mark if cared for and not abused.
Have fun and be super careful!
Sam:biggrin:
