I have spent a long time looking around for an answer to this but no luck.

I just took out my air box and replaced with a uni filter. It looks pretty sweet and i'm stooked to try it.

Just wondering though, there was a tub that plugged into the side of the air box (which it then runs into a small box and then into the ignition case area. now that i have a foam air filter on i don't have anywhere to plug this tube and i dont know what it does. Is it the "crankcase vent" and i i should buy an external filter for it like this http://xr50.com/ap8mmcrvefi.html ? If so, is it possible to run without a filter or will dirt be sucked in or gas and junk leak out or what?

Im amazingly confused here and want to start this bike up. Thanks for your help!