Abstract: A boat propulsion device is configured to be attachable to a vessel body including an external tank. The boat propulsion device includes an engine, an exhaust pipe, a catalyst, an internal tank, a detection unit and a control unit. The exhaust pipe is connected to the engine. The catalyst is disposed in the exhaust pipe. The internal tank communicates with the external tank. The internal tank is configured to store a fuel to be supplied to the engine. The detection unit is configured to detect whether or not an amount of fuel remaining within the internal tank is less than or equal to a predetermined remaining amount. The control unit is configured or programmed to perform a rotation speed reduction control to reduce a rotation speed of the engine when the detection unit has detected that the amount of fuel remaining within the internal tank had become less than or equal to the predetermined remaining amount.

Abstract: A dog clutch selectively meshes with a forward gear and a reverse gear according to an operation of a shift operating member such that connection of the forward gear or the reverse gear to a propeller shaft is changed. A friction clutch transmits the rotation of a drive shaft to the propeller shaft by a first friction surface and a second friction surface contacting together. Before a shifting stage in which the dog clutch meshes with the forward gear or with the reverse gear, a control unit is configured or programmed to control an actuator so as to execute synchronization control by making the first friction surface and the second friction surface of the friction clutch contact one another.

Abstract: An outboard motor includes an engine, a drive shaft, a drive gear, a propeller shaft, a forward gear, a reverse gear, a dog clutch, and a friction clutch. The drive shaft extends downward from the engine. The drive gear is fixed to the drive shaft. The propeller shaft extends in a direction to intersect the drive shaft. The forward gear is meshed with the drive gear. The reverse gear is meshed with the drive gear. The dog clutch is disposed on the propeller shaft, and changes between connecting the forward gear to the propeller shaft, and connecting the reverse gear to the propeller shaft. The friction clutch is disposed in sequence with the dog clutch along the axial direction of the propeller shaft, and transmits rotation of the drive shaft to the propeller shaft by frictional force.

Abstract: A dog clutch selectively meshes with a forward gear and a reverse gear according to an operation of a shift operating member such that connection of the forward gear or the reverse gear to a propeller shaft is changed. A friction clutch transmits the rotation of a drive shaft to the propeller shaft by a first friction surface and a second friction surface contacting together. Before a shifting stage in which the dog clutch meshes with the forward gear or with the reverse gear, a control unit is configured or programmed to control an actuator so as to execute synchronization control by making the first friction surface and the second friction surface of the friction clutch contact one another.

Abstract: An outboard motor includes an engine, a drive shaft, a drive gear, a propeller shaft, a forward gear, a reverse gear, a dog clutch, and a friction clutch. The drive shaft extends downward from the engine. The drive gear is fixed to the drive shaft. The propeller shaft extends in a direction to intersect the drive shaft. The forward gear is meshed with the drive gear. The reverse gear is meshed with the drive gear. The dog clutch is disposed on the propeller shaft, and changes between connecting the forward gear to the propeller shaft, and connecting the reverse gear to the propeller shaft. The friction clutch is disposed in sequence with the dog clutch along the axial direction of the propeller shaft, and transmits rotation of the drive shaft to the propeller shaft by frictional force.

Abstract: A boat propulsion device is configured to be attachable to a vessel body including an external tank. The boat propulsion device includes an engine, an exhaust pipe, a catalyst, an internal tank, a detection unit and a control unit. The exhaust pipe is connected to the engine. The catalyst is disposed in the exhaust pipe. The internal tank communicates with the external tank. The internal tank is configured to store a fuel to be supplied to the engine. The detection unit is configured to detect whether or not an amount of fuel remaining within the internal tank is less than or equal to a predetermined remaining amount. The control unit is configured or programmed to perform a rotation speed reduction control to reduce a rotation speed of the engine when the detection unit has detected that the amount of fuel remaining within the internal tank had become less than or equal to the predetermined remaining amount.