The purpose of this invention is to improve lubricating performance in an engine by improving scraped up oil recovering efficiency by optimization of a scraped up oil recovering structure. Oil scraped up by the rotation of a clutch 2b is collected by a collecting means formed as a grooved recess 13d arranged in a case cover annular inner circumferential surface 13c faced to a clutch peripheral part 2b1. Collected oil is guided with a smooth flow to the recovered oil receiver 11A of a crank case 10 through the bent upper edge part 15i of an oil guide plate 15. Recovered oil is supplied from the drop hole 10C1 of a recovered oil passage 10C to the gear meshing part of a transmission gear mechanism below the passage 10C.