Outboard motor including drive shaft vibration damper

摘要

An outboard motor that is capable of reducing a trolling noise includes an engine which has a crank shaft extending in an up-down direction; a drive shaft extending downward from the crank shaft and including a torsion bar spring; a propeller shaft; a propeller provided in the propeller shaft; a forward/backward switching mechanism arranged to connect the drive shaft and the propeller shaft with each other; and a vibration damper which includes a first cylindrical body and a second cylindrical body which are penetrated by the torsion bar spring. The first cylindrical body and the second cylindrical body are coaxial with each other. The first cylindrical body has its upper end portion connected with an upper end portion of the torsion bar spring whereas the second cylindrical body has its lower end portion connected with a lower end portion of the torsion bar spring. A viscous fluid is filled between the first cylindrical body and the second cylindrical body.