STRUCTURE OF INTERNAL COMBUSTION ENGINE

摘要

The structure comprises a cylinder which accomodates a piston connected with a crankshaft and a crankshaft provided to accomodate the crankshaft. A rocker case is provided to accomodate a valve actuating mechanism. An oil return passage leads oil in the rocker case into the crankcase. A restrainer restrains air flow within the crankcase from entering into the oil return passage.