Abstract: A motorcycle engine having a cooling device is constructed as an OHC type multi-cylinder engine arranged on a vehicle frame with a plurality of cylinders being aligned perpendicularly to the longitudinal direction of the body frame, wherein a radiator provided with a forced cooling fan and a carburetor leading to engine intake ports are disposed forwardly and rearwardly of the engine, respectively, a timing transmission device for driving a valve-actuating cam shaft of the engine is arranged so as to deviate to one side from the center of the cylinder block in the alignment direction of said cylinders, the timing transmission device and the radiator fan being arranged side-by-side in the longitudinal direction of the frame, a plurality of bearing holders are provided separately on the engine cylinder head correspondingly to the cylinders to rotatably support a valve-actuating cam shaft extending in the alignment direction of the cylinders, and a head cover covering the cylinder head provides wind guiding pass

Abstract: A hydraulically operated friction clutch suitable for use in motorcycle. The clutch has driving and driven friction discs axially slidably mounted on a clutch outer and a clutch inner, respectively. These friction discs are adapted to be pressed onto a pressure receiving plate by a pressing plate to make friction driving engagement between the clutch outer and the clutch inner. An annular carrier integrated with the pressing plate is disposed at the opposite side of the clutch inner to the pressing plate. A pressure receiving member is mounted on the center of the carrier through a release bearing adjacent to the end of a driven shaft connected to the clutch inner. The pressure receiving member has a cylindrical form closed at its one end and provided at its open end with a flange which is retained by the inner race of the release bearing. The pressure receiving member is coaxially and axially movably received in a bore formed in the driven shaft.