Well, I found out the problem. He was mixing in 4 stroke oil instead of 2 stroke, so the plug was fouled. Replaced the plug, cleaned the carb, replaced the air filter, put new gas in, and she started right up.
Got to ride her around, and she is fast! Now there's either a throttle issue or an idle issue, because when I'm not in gear (clutch in or in neutral) she revs very high. Tach is broken, but it's way wrong. He thinks it's the throttle sticking. Also, that headlight SUCKS. Need to upgrade that if I'm every going to ride at night again.