I've got a 1977 Vespa Ciao- i just bought it maybe two months ago. it's my first moped. from the outset, it's had some problems starting without giving the throttle some gas to get it going, and some real problems idling before being warmed up. in addition, it has the nasty habit of dying at red lights. when it's running, it runs fine.
i brought it back to the guy who sold it to me, since he was nice enough to offer some service on the bike. we took apart the carb and cleaned it, changed sparkplugs, adjusted the idle, etc, and it seemed to be doing ok. as soon as i got it home, it was up to the same old behavior again. any tips/ideas/directions as to what might be the culprit?