A power unit, comprising: a main shaft having a plurality of first gears (47A, 47B, 47C, 47D, 47E, 47F) including a first movable gear (47C, 47D) that is movable around an axis of the main shaft; a drive shaft having a plurality of second gears (49A, 49B, 49C, 49D, 49E, 49F) including a second movable gear (49B, 49E) that is movable around an axis of the drive shaft, the second gears (49A, 49B, 49C, 49D, 49E, 49F) being configured to intermesh with the first gears (47A, 47B, 47C, 47D, 47E, 47F); a shift fork configured to engage with the first movable gear (47C, 47D) and the second movable gear (49B, 49E); a shift drum having a groove with which the shift fork engages; a crankcase housing the main shaft, the drive shaft, the shift fork and the shift drum; a rotation plate fixed to an end of the shift drum, to thereby rotate with the shift drum, the rotation plate including an outer peripheral surface having a plurality of recessed portions; a shift lever configured to engage with the rotation plate; a shift shaft fixed to the shift lever; a support shaft disposed substantially in parallel with the shift drum; a stopper lever, including a first end portion and a second end portion that is rotatably supported by the support shaft; a stopper roller disposed between the first end portion and the second end portion of the stopper lever, and being configured to engage with one of the recessed portions of the rotation plate; and an elastic member including a first engagement end portion that is configured to engage with the first end portion of the stopper lever, and a second engagement end portion that is configured to engage with the crankcase, so as to apply a force to the stopper lever to thereby press the stopper roller against the one recessed portion, and characterised in that the stopper lever is so disposed as to, when viewed in an axial direction of the shift shaft, intersect a first line segment that connects a center of the shift shaft to a center of the rotation plate. a main shaft having a plurality of first gears (47A, 47B, 47C, 47D, 47E, 47F) including a first movable gear (47C, 47D) that is movable around an axis of the main shaft; a drive shaft having a plurality of second gears (49A, 49B, 49C, 49D, 49E, 49F) including a second movable gear (49B, 49E) that is movable around an axis of the drive shaft, the second gears (49A, 49B, 49C, 49D, 49E, 49F) being configured to intermesh with the first gears (47A, 47B, 47C, 47D, 47E, 47F); a shift fork configured to engage with the first movable gear (47C, 47D) and the second movable gear (49B, 49E); a shift drum having a groove with which the shift fork engages; a crankcase housing the main shaft, the drive shaft, the shift fork and the shift drum; a rotation plate fixed to an end of the shift drum, to thereby rotate with the shift drum, the rotation plate including an outer peripheral surface having a plurality of recessed portions; a shift lever configured to engage with the rotation plate; a shift shaft fixed to the shift lever; a support shaft disposed substantially in parallel with the shift drum; a stopper lever, including a first end portion and a second end portion that is rotatably supported by the support shaft; a stopper roller disposed between the first end portion and the second end portion of the stopper lever, and being configured to engage with one of the recessed portions of the rotation plate; and an elastic member including a first engagement end portion that is configured to engage with the first end portion of the stopper lever, and a second engagement end portion that is configured to engage with the crankcase, so as to apply a force to the stopper lever to thereby press the stopper roller against the one recessed portion, and characterised in that the stopper lever is so disposed as to, when viewed in an axial direction of the shift shaft, intersect a first line segment that connects a center of the shift shaft to a center of the rotation plate.