Abstract: An outboard engine assembly has an engine unit including an engine unit housing, an internal combustion engine disposed in the engine unit housing, the engine defining at least one combustion chamber, a gearcase connected to the engine unit housing, and an exhaust system, the exhaust system including an idle relief passage fluidly communicating with an exhaust passage, the idle relief passage having an idle relief outlet, the idle relief passage extending through the engine unit housing for supplying exhaust gases from the at least one combustion chamber to an exterior of the engine unit housing via the idle relief outlet, the idle relief outlet being disposed vertically higher than the exhaust outlet and vertically lower than a waterline when the outboard engine assembly is mounted to a watercraft and the watercraft is at rest, and a propulsion device operatively connected to the engine.

Abstract: A marine motor assembly for mounting to a watercraft is disclosed. The marine motor assembly has a motor unit including a motor unit housing, a motor, a propulsion device, an air pump fluidly communicating with an under-housing volume of the motor unit housing, a pressure sensor for measuring air pressure in the under-housing volume, and a control unit communicating with the air pump and the pressure sensor. The control unit is programmed for controlling the air pump for changing air pressure in the under-housing volume, and monitoring change in the air pressure for a predetermined amount of time for confirming that the motor unit housing is water-resistant, or that the water resistance of the motor unit housing is compromised. A method for testing a water resistance of a motor unit housing of a marine motor assembly is also disclosed.

Abstract: A marine engine assembly for mounting to a watercraft is disclosed. The marine engine assembly has an engine unit, an exhaust system fluidly and a propulsion device. The engine unit includes an engine unit housing, an internal combustion engine and an air intake assembly. The air intake assembly, at least one combustion chamber, and the exhaust system together defining at least in part a gas flow pathway. A sealing valve is provided in the gas flow pathway. The sealing valve has an open position permitting flow of gas therethrough. The sealing valve has a closed position preventing flow of gas therethrough for sealing a portion of the gas flow pathway downstream of the sealing valve from a portion of the gas flow pathway upstream of the sealing valve.

Abstract: An outboard engine assembly has an engine unit including an engine unit housing, an internal combustion engine disposed in the engine unit housing, the engine defining at least one combustion chamber, an exhaust system fluidly communicating with the at least one combustion chamber for supplying exhaust gases from the at least one combustion chamber to an exterior of the outboard engine assembly, a gearcase connected to the engine unit housing, a control module connected to the engine for controlling at least one operating parameter of the outboard engine assembly, and a water sensor disposed at least in part in the exhaust system for detecting presence of water in the exhaust system, the water sensor being in communication with the control module, and a propulsion device operatively connected to the engine.

Abstract: A marine engine assembly for mounting to a watercraft is disclosed. The marine engine assembly has an engine unit, an exhaust system fluidly and a propulsion device. The engine unit includes an engine unit housing, an internal combustion engine and an air intake assembly. The air intake assembly, at least one combustion chamber, and the exhaust system together defining at least in part a gas flow pathway. A sealing valve is provided in the gas flow pathway. The sealing valve has an open position permitting flow of gas therethrough. The sealing valve has a closed position preventing flow of gas therethrough for sealing a portion of the gas flow pathway downstream of the sealing valve from a portion of the gas flow pathway upstream of the sealing valve. An air pump is configured for supplying air to the gas flow pathway downstream of the sealing valve.

Abstract: An exhaust valve system for a two-stroke internal combustion engine having: at least one exhaust valve movable between open and closed positions; an actuator for moving the at least one exhaust valve; a valve position sensor; a controller communicating with the actuator and the valve position sensor. The controller being programmed for: controlling the actuator to attempt to move the at least one exhaust valve to a desired one of the open and closed positions; determining if the at least one exhaust valve has failed to reach the desired position based on the position of the at least one exhaust valve sensed by the valve position sensor; and controlling the actuator to move the at least one exhaust valve to an intermediate position when the at least one exhaust valve has failed to reach the desired position.

Abstract: An exhaust valve system for a two-stroke internal combustion engine having: at least one exhaust valve movable between open and closed positions; an actuator for moving the at least one exhaust valve; a valve position sensor; a controller communicating with the actuator and the valve position sensor. The controller being programmed for: controlling the actuator to attempt to move the at least one exhaust valve to a desired one of the open and closed positions; determining if the at least one exhaust valve has failed to reach the desired position based on the position of the at least one exhaust valve sensed by the valve position sensor; and controlling the actuator to move the at least one exhaust valve to an intermediate position when the at least one exhaust valve has failed to reach the desired position.

Abstract: A two-stroke internal combustion engine has an engine block having a cylinder block and a cylinder head. The cylinder block defines a cylinder, an exhaust passage, and an exhaust valve passage. The engine also has a piston, an exhaust valve actuator operatively connected to at least one of the cylinder block and the cylinder head, and a reciprocating exhaust valve disposed at least in part in the exhaust valve passage. The exhaust valve has a shaft operatively connected to a valve actuator, and a blade connected to the shaft. A channel is defined along a face of the blade. The channel and a wall of the exhaust valve passage together define at least in part a valve passage. The valve passage permits flow of exhaust gas along the face of the blade. A width of the valve passage is at least a third of a width of the blade.

Abstract: A marine outboard engine includes an internal combustion engine including at least one fuel injector; a fuel vapor separator including: a separator body, a fuel reservoir defined by the separator body, and a first fuel pump fluidly connected between the fuel reservoir and the fuel injector; a fuel tank; and a second fuel pump fluidly connected between the fuel tank and the fuel vapor separator. The fuel vapor separator includes a heat exchanger disposed in the separator body. The heat exchanger includes at least one fuel channel defined by the heat exchanger body, the at least one fuel channel including: an inlet adapted for receiving fuel from the engine, and an outlet fluidly communicating with the fuel reservoir; and at least one coolant channel defined by the heat exchanger body, the at least one fuel channel and the at least one coolant channel being in thermal communication.

Abstract: A marine outboard engine includes an internal combustion engine including at least one fuel injector; a fuel vapor separator including: a separator body, a fuel reservoir defined by the separator body, and a first fuel pump fluidly connected between the fuel reservoir and the fuel injector; a fuel tank; and a second fuel pump fluidly connected between the fuel tank and the fuel vapor separator. The fuel vapor separator includes a heat exchanger disposed in the separator body. The heat exchanger includes at least one fuel channel defined by the heat exchanger body, the at least one fuel channel including: an inlet adapted for receiving fuel from the engine, and an outlet fluidly communicating with the fuel reservoir; and at least one coolant channel defined by the heat exchanger body, the at least one fuel channel and the at least one coolant channel being in thermal communication.