Abstract: A cylinder primary air filter element is coaxially disposed within a cylindrical shell between an air intake pipe and an outlet provided in the shell. A resilient secondary air filter element is deformably secured in an opening formed in a sidewall of the shell so as to be located outside the outer periphery of the primary air filter. The secondary filter element is secured in place by a filter element retaining plate which is arcuately shaped so as to be concentric with the primary filter element and is readily detachably attached to the shell. A sufficiently enlarged air flow passageway is thus defined between the outer periphery of the primary air filter element and the filter element retaining plate and consequently the resistance encountered by the air flowing through this passageway may be considerably reduced and the excessive bulging of the air cleaner may be avoided. A reed valve assembly is connected to the outlet of a housing which surrounds the secondary filter element.