Where is the air filter on Craftsman Model 917377660 lawn mower

If you have a briggs or a tecumsen it is mounted on the side mounted on the top side of the carburator, one is a round cylindrical filter with a steel or plastic mesh surrounding and the other is a rather flat 3"X5" filter also mounted under a single center screw and cover.The third type is an oil bath type sponge filter, mounted directly on top of the carburetor on the side of the engine, you replace the sponge and clean out the metal housing held down with one long screw through its top center.