Oil circulation structure for motorcycle and tricycle engines

摘要

The structure includes an oil storage chamber (125) arranged at the backside of a crankshaft (12) accommodated in a crank case (124). A return pump (127) attached to the lower part of a crankcase (14) in front of the crankshaft. A return pipe (145) is arranged at the downward direction of the crankshaft within the crankcase and guides the oil discharged from the return pump on oil storage chamber side.