If the bike refuses to run at all, check the air filter, the carburetor boots, and the airbox. Unless one of these three things is completely dislodged, air is probably not the source of your problem. If it is dislodged, reconnect it. If not, then continue to another part of the algorithm, as air is not likely the main cause of your problem. Check for fuel, spark, and compression first, and see if that will get you going.