Patent ID: 7448355

Claim:
An integrated power unit for a small vehicle, the power unit comprising: a crankshaft; a transmission shaft; a crankcase, the crankcase being split into an upper crankcase and a lower crankcase; a crank chamber formed within the crankcase, the crankshaft rotatably supported within the crank chamber and having an axis which is oriented in a transverse direction which is orthogonal to a forward travel direction of the vehicle; a transmission chamber within the crankcase on a rear side of the crank chamber, the transmission shaft rotatably supported within the transmission chamber; and a clutch which permits connection and disconnection of power of the crankshaft to and from the transmission shaft, the clutch disposed at one end of the transmission shaft, wherein respective confronting surfaces of the upper crankcase and the lower crankcase are provided with a plurality of fastening boss portions arranged as vertically opposed pairs, the upper crankcase and the lower crankcase are fastened together by fastening the respective vertically opposed pairs of the fastening boss portions using fastening bolts so as to integrate the upper crankcase and the lower crankcase into a single entity, wherein rearmost ones of the plurality of fastening boss portions are located so as to be vertically overlapping with a rear portion of the clutch, and wherein the rearmost fastening boss portions are set at a position near a rear corner portion of the crankcase.