Abstract: A tilting mechanism including a tilt locking mechanism for releasably retaining an outboard drive unit in a tilted down position under normal running conditions and a tilt holding mechanism for releasably holding the outboard drive unit in a tilted up position is constructed and arranged so that a lever of the tilt locking mechanism lever and a holder arm of the holding mechanism pivot about a common axis, preferably about a single support shaft, on the swivel bracket.

Abstract: An improved vibration damping structure for an outboard drive having a drive shaft housing with a pair of spaced apart side walls. A resilient coupling is provided between the spaced side walls for damping vibrations.

Abstract: An outboard drive arrangement having a drive shaft housing having spaced walls defining a hollow interior. An exhaust pipe extends into the hollow interior and resilient elements are interposed between the exterior walls of the exhaust pipe and the interior walls of the drive shaft housing for providing a resilient connection therebetween for damping vibrations.

Abstract: A number of embodiments of coupling arrangements for coupling a propeller to a driving shaft that permit a higher degree of resilience in a circumferential direction than in an axial direction. As a result, the coupling may be designed so as to offer high degree of vibration damping while affording good resistance to axial driving thrust. In addition, each embodiment is designed so as to provide more resilience in the reverse drive condition than in the forward drive condition.

Abstract: Marine propulsion unit having a propeller assembly formed with exhaust gas passages through the propeller hub. An outer pipe is provided to encircle the propeller hub with a radial spacing and has a rear end extending beyond the rear end of the hub. The rear end of the exhaust gas is decreased in diameter at the rear end portion thereof so that the rear end opening of the outer pipe is smaller in diameter than the propeller hub so that the exhaust gas is forced to flow, during a reverse movement, from the exhaust gas passage in the hub to the space between the hub and the outer pipe. For facilitating manufacture of the outer pipe through conventional casting technique, the outer pipe is comprised of a front and rear parts which are mated together.