A power unit for a motorcycle includes an internal combustion engine having a crankcase rotatably supporting a crankshaft with an axis located on a split face between an upper case half body and a lower case half body and a continuously variable transmission having a belt. Two types of respective different oils for an internal combustion engine and for a continuously variable transmission are used while the rigidity of the crankcase is enhanced. A crankcase is provided with a partition wall that separates between a crank chamber housing a crankshaft and a continuously variable transmission chamber housing a continuously variable transmission. An axial line of the crankshaft and respective axial lines of the drive pulley and the driven pulley are each located at a corresponding one of apexes of an imaginary triangle on a view projected on a plane perpendicular to the axial line of the crankshaft.