A four cycle engine having at least one cylinder unit is disclosed. The engine includes a continuously variable transmission (CVT) connected to the engine on one side of the engine. An air box is also provided that is located on the same side of the engine as the CVT. The engine further includes an intake manifold operatively connected to the air box for connecting the air box to each cylinder unit and a throttle assembly operatively connected to air box and the intake manifold. The intake manifold may have a generally Y-shaped manifold having a connector leg connected to the throttle assembly and a pair of branches. One branch is operatively connected to one of the cylinder units and another branch is connected to another of the cylinder units. The connector leg is generally parallel to the axis of the crankshaft. The intake manifold may further include a baffle assembly, which directs gas flow within the intake manifold.