Power unit for vehicle

A vehicle power unit comprising:

• a speed reducing gear train including a starter driven gear selectively rotatably mounted on a crankshaft, said crankshaft being rotatably mounted on a crankcase constituting part of an engine body;
• a starting one-way clutch interposed between the starter driven gear and the crankshaft so as to permit power transmission from the starter driven gear to the side of the crankshaft, the speed reducing gear train and the starting one-way clutch being provided between a starter motor mounted to the engine body and the crankshaft;
• a transmission accommodated in the crankcase, the transmission having gear trains for a plurality of gear speeds which can be selectively established, the gear trains being provided between a main shaft and a counter shaft which have axes parallel to the crankshaft;
• and
• a power transmitting gear meshing with the starter driven gear is selectively rotatably mounted on the main shaft through a running one-way clutch to transmit rotation from the power transmitting gear to the main shaft,
• wherein the starter driven gear includes a rotary member selectively rotatably mounted on the crankshaft through the starting one-way clutch interposed between the rotary member and the crankshaft, a gear member selectively rotatably mounted on the crankshaft and meshing with the power transmitting gear and a shifter mounted on the rotary member to be axially movable in a direction along the axis of the crankshaft and to be incapable of rotation, said shifter including a dog selectively engagable and disengagable with the gear member.