An apparatus and methods are provided for an air cleaner to be mounted onto an air inlet of an internal combustion engine. The air cleaner comprises an air filter that includes a filter medium disposed between a curved base and a cover. The curved base provides an interface between the air filter and the air inlet, and comprises a shape that provides clearance between the curved base and an electric choke installed onto a carburetor comprising the air inlet. The cover secures the air filter and the curved base to the air inlet such that an airstream is drawn through the filter medium and is conducted into the air inlet. A raised portion of the cover is configured to cooperate with the curved base to ensure a desired volume of the airstream is available to the air inlet at substantially all engine speeds.