Patent attributes
An outboard motor includes a variable speed mechanism portion arranged to transmit a driving force to propellers such that the driving force is changed in its speed by a low reduction ratio and a high reduction ratio, an upper housing that houses the variable speed mechanism portion, oil tanks provided on the outside of the upper housing and arranged to retain oil to be supplied to the upper housing, and an oil lubrication route arranged to supply oil in the oil tanks to the upper housing and to collect the oil supplied in the upper housing in the oil tanks. The above arrangement provides a boat propulsion unit capable of allowing both a performance of acceleration and a maximum speed to approach a level desired by a user and to prevent the occurrence of a loss of the driving energy of an engine.