dude yo. urban expresses are sweet, so wierd lookin. not technically a moped tho, so you'll probably be called a fuckface by someone. also theres a special forum called "repair" that would probably fit your q better.
ecplain how you mean by barely runs. Theres a bunch of stuff into and out of that carb - check the manual here;
the only ones that matter are the 2 autochoke ones and the gas line. I'd plug up the oil line and run premix, at least to check if the oil pump is working.
theres a bunch of other things too, but i'd def recommend a 17321 belt