Someone beat me to that quadAnything can be fixed and parts are pretty cheap. $90 at hk motos will get you a billet alum Winged Head/Cyld 49cc kit, from FC crank, to piston, rocket key and gaskets, everything.
Looks to new for a bad engine, more likely the main jet is clogged and it has been sitting awhile & the float bowl is a mess from gummed up gas. I might go $100 or $150.
The part your referring to is the EPA smog tube and probably goes to the airbox...........Its probably bypassed to enhance power and performance......Offer him $160.00this is the 2007 49cc mta1 s4 cobra mini cobra. I went & looked at it in person. It needs rust removal,tires,brakes,entire engine repair/carb maybe even a new engine.chain is ok,the throttle is fine,the flairings are ok enough to not be an eye sore.The guy wants $275. Also there's a black rubber hose that connect to the muffler with some metal connector.The hose has some fuel filter shaped thing at the end.
Sorry didnt take more pics.
Does any1 know what that hose does/connects to? btw it does look nice in the pic.very different in person.still would be a nice project to take on but not worth $200.
Anthony