after sitting for a long long time, you'll probably just have to let it run for a while before it starts to idle. my bianchi was out of commission for about 3 months. and then i replaced the engine (not sure how long that wasn't running) and it runs fine, but it took it a few days to start to idel. i guess it just needs to get the juices flowing again. now it idles sooner and sooner after a start (except for the first start of the day, of course).
if you need/want parts, call handybikes. they have pretty much everything, it seems. i just ran into a kid w/ a 1979 pa50 today ... he did 40mph easy. nice bike.