Abstract: A marine propulsion system includes a first marine propulsion device and a second marine propulsion device. The first marine propulsion device includes an engine, a first propeller shaft to receive a driving force from the engine, and a first controller configured or programmed to control the engine. The second marine propulsion device includes an electric motor, a second propeller shaft to receive a driving force from the electric motor, an electric circuit connected to the electric motor to drive the electric motor, and a second controller configured or programmed to control the electric motor. The first controller is configured or programmed to put a limitation on an output of the engine when the electric motor is not being driven.

Abstract: A marine vessel power supply system for a marine vessel including an electric motor to rotate a propeller includes an inverter to supply electric power to the electric motor, a battery to supply electric power to the inverter, and an electronic control unit configured or programmed to control the inverter. The inverter includes an inverter circuit to convert DC electric power supplied from the battery to AC electric power, a voltage detector to detect the voltage in a wiring between the battery and the inverter circuit, and a microcomputer configured or programmed to communicate with the electronic control unit and to control the inverter circuit according to a command supplied from the electronic control unit. The electronic control unit calculates an SOC estimate indicative of an estimated state-of-charge value of the battery based on a value of the voltage detected by the voltage detector and acquired from the microcomputer.

Abstract: A marine propulsion system includes marine propulsion devices each including a propeller shaft, an engine, an electric motor, a power transmission to transmit mechanical power to the propeller shaft from at least one of the engine and the electric motor, an electric circuit connected to the electric motor, and a controller to control the engine. The controllers in the marine propulsion devices are communicable with each other when in a communicable state. When the controller in each of the marine propulsion devices is in the communicable state, but the controller of one of the marine propulsion devices is incommunicable with any other controller of the marine propulsion devices, the incommunicable controller limits an output of the engine controlled by the incommunicable controller.

Abstract: A marine propulsion system includes marine propulsion devices each including a propeller shaft, an engine, an electric motor, a power transmission, an inverter, a voltage sensor, and a controller. The power transmission transmits mechanical power to the propeller shaft from at least one of the engine and the electric motor. The inverter outputs electric power inputted thereto to the electric motor after converting the electric power. The voltage sensor detects induced voltage generated by the electric motor. The controller executes a protection control to protect the inverter when the induced voltage is greater than a first threshold while the electric motor is not being driven.

Abstract: A marine vessel power supply system for a marine vessel including an electric motor to rotate a propeller includes an inverter to supply electric power to the electric motor, a battery to supply electric power to the inverter, and an electronic control unit configured or programmed to control the inverter. The inverter includes an inverter circuit to convert DC electric power supplied from the battery to AC electric power, a voltage detector to detect the voltage in a wiring between the battery and the inverter circuit, and a microcomputer configured or programmed to communicate with the electronic control unit and to control the inverter circuit according to a command supplied from the electronic control unit. The electronic control unit calculates an SOC estimate indicative of an estimated state-of-charge value of the battery based on a value of the voltage detected by the voltage detector and acquired from the microcomputer.

Abstract: A marine propulsion system includes marine propulsion devices each including a propeller shaft, an engine, an electric motor, a power transmission to transmit mechanical power to the propeller shaft from at least one of the engine and the electric motor, an electric circuit connected to the electric motor, and a controller to control the engine. The controllers in the marine propulsion devices are communicable with each other when in a communicable state. When the controller in each of the marine propulsion devices is in the communicable state, but the controller of one of the marine propulsion devices is incommunicable with any other controller of the marine propulsion devices, the incommunicable controller limits an output of the engine controlled by the incommunicable controller.

Abstract: A marine propulsion system includes marine propulsion devices each including a propeller shaft, an engine, an electric motor, a power transmission, an inverter, a voltage sensor, and a controller. The power transmission transmits mechanical power to the propeller shaft from at least one of the engine and the electric motor. The inverter outputs electric power inputted thereto to the electric motor after converting the electric power. The voltage sensor detects induced voltage generated by the electric motor. The controller executes a protection control to protect the inverter when the induced voltage is greater than a first threshold while the electric motor is not being driven.

Abstract: An outboard motor includes a vapor separator tank, a downstream fuel supply path, a fuel pump that discharges a fuel in the vapor separator tank into the downstream fuel supply path, a downstream bypass path, and a downstream relief valve provided in the downstream bypass path. A first end of the downstream bypass path is connected to a downstream portion that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path, and a second end of the downstream bypass path is connected to an upstream portion between the downstream check valve and the vapor separator tank in the downstream fuel supply path. The downstream relief valve opens the downstream bypass path when a fuel pressure in a downstream region that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path exceeds a first predetermined value.

Abstract: An outboard motor includes an engine, an engine cover accommodating the engine, and an intake path between the engine cover and the engine. The intake path directs external air to the engine. The engine cover includes an upper cover and a lower cover. The upper cover includes an opening to take external air into the intake path. The intake path includes a first airflow passage, a second airflow passage, and an airflow space. The first airflow passage is at least partially defined by an inner surface of the engine cover, and downwardly directs the external air. The second airflow passage is at least partially defined by the inner surface of the engine cover, and upwardly directs the external air. The airflow space is above the lower cover and continues to the first airflow passage and the second airflow passage.

Abstract: An outboard motor includes a vapor separator tank, a downstream fuel supply path, a fuel pump that discharges a fuel in the vapor separator tank into the downstream fuel supply path, a downstream bypass path, and a downstream relief valve provided in the downstream bypass path. A first end of the downstream bypass path is connected to a downstream portion that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path, and a second end of the downstream bypass path is connected to an upstream portion between the downstream check valve and the vapor separator tank in the downstream fuel supply path. The downstream relief valve opens the downstream bypass path when a fuel pressure in a downstream region that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path exceeds a first predetermined value.

Abstract: An outboard motor includes a cylinder block, a cylinder head unit, a delivery pipe, a plurality of injectors, a fuel pump, and a fuel pipe. The cylinder block includes a plurality of cylinders. The cylinder head unit is connected to the cylinder block. The delivery pipe is attached to the cylinder head unit. The injectors are attached to the delivery pipe. The fuel pump is attached to the cylinder head unit. The fuel pipe is attached to the delivery pipe and the fuel pump. A first attachment direction of attaching the fuel pump to the cylinder head unit is parallel or substantially parallel to a second attachment direction of attaching the fuel pipe to the delivery pipe.

Abstract: An outboard motor includes a crankshaft, a first bank including a plurality of first cylinders, a second bank including a plurality of second cylinders, a plurality of first injectors, a plurality of first spark plugs, a plurality of second injectors, and a plurality of second spark plugs. Each of the first and second cylinders includes a combustion chamber, an intake port, and an exhaust port. The first injectors and the first spark plugs are alternately disposed in a vertical direction. The second injectors and the second spark plugs are alternately disposed in the vertical direction in a reverse order to that of the first injectors and the first spark plugs. When the crankshaft is seen from a horizontal direction, the first cylinders and the second cylinders are disposed symmetrically about a point of symmetry arranged on an axis of the crankshaft.

Abstract: An outboard motor includes a crankshaft, a first bank including a plurality of first cylinders, a second bank including a plurality of second cylinders, a plurality of first injectors, a plurality of first spark plugs, a plurality of second injectors, and a plurality of second spark plugs. Each of the first and second cylinders includes a combustion chamber, an intake port, and an exhaust port. The first injectors and the first spark plugs are alternately disposed in a vertical direction. The second injectors and the second spark plugs are alternately disposed in the vertical direction in a reverse order to that of the first injectors and the first spark plugs. When the crankshaft is seen from a horizontal direction, the first cylinders and the second cylinders are disposed symmetrically about a point of symmetry arranged on an axis of the crankshaft.

Abstract: An outboard motor includes a cylinder block, a cylinder head unit, a delivery pipe, a plurality of injectors, a fuel pump, and a fuel pipe. The cylinder block includes a plurality of cylinders. The cylinder head unit is connected to the cylinder block. The delivery pipe is attached to the cylinder head unit. The injectors are attached to the delivery pipe. The fuel pump is attached to the cylinder head unit. The fuel pipe is attached to the delivery pipe and the fuel pump. A first attachment direction of attaching the fuel pump to the cylinder head unit is parallel or substantially parallel to a second attachment direction of attaching the fuel pipe to the delivery pipe.