A marine drive is for propelling a marine vessel. The marine drive includes: an engine; an exhaust manifold that conveys exhaust gas from the engine; a cooling jacket on the exhaust manifold, wherein a cooling passage is defined between the cooling jacket and the exhaust manifold; a cooling pump that pumps cooling fluid through the cooling passage so as to cool the exhaust manifold and the exhaust gas; a power steering actuator configured to steer the marine drive relative to the marine vessel; a power steering pump that pumps power steering fluid from a power steering reservoir to the power steering actuator; and a power steering cooler on the exhaust manifold and configured such that the power steering fluid is cooled by the cooling fluid in the cooling passage. In some examples the marine drive is configured for use in an outboard motor.

An outboard motor includes an engine, an electric motor, a propeller that rotates due to a driving force from the engine and a driving force from the electric motor, and an anti-cavitation plate disposed above the propeller. At least a portion of the electric motor is disposed above the anti-cavitation plate and below a waterline of an outboard motor body.

A mobile emissions control system is provided for diesel engines operated on ocean-going ships at-berth. The emissions control system comprises two essential elements: an emissions capturing system and an emissions control system. The emissions control system may be mounted on a towable chassis or mounted on a barge, allowing it to be placed alongside ocean-going ships at-berth. The emission capturing system captures exhaust from a ship's diesel engine and conducts it into the emissions control system, which cleans the exhaust and then passes clean air into the atmosphere through an exhaust outlet.

An exhaust system for a marine outboard engine including an engine having an engine exhaust port. The exhaust system includes a first exhaust port, a second exhaust port vertically higher than the first exhaust port, a first passage for fluidly connecting to the engine exhaust port and fluidly connected to the first exhaust port, a second passage fluidly connected between the first passage and the second exhaust port, a catalytic converter defining at least in part the second passage, a valve operable to at least partially close the first passage to respectively reduce and increase flow of exhaust gas to the first exhaust port and the second exhaust port, a valve actuator operatively connected to the valve, and a controller operatively connected to the valve actuator for controlling a position of the valve based at least in part on a speed and a throttle request of the engine.

An outboard motor has a powerhead that causes rotation of a driveshaft, a steering housing located below the powerhead, wherein the driveshaft extends from the powerhead into the steering housing; and a lower gearcase located below the steering housing and supporting a propeller shaft that is coupled to the driveshaft so that rotation of the driveshaft causes rotation of the propeller shaft. The lower gearcase is steerable about a steering axis with respect to the steering housing and powerhead.

A marine propulsion device includes an internal combustion engine powering the marine propulsion device and an engine compartment containing the engine. A primary exhaust passageway routes exhaust gas away from the engine and out of the engine compartment. A sound enhancement assembly communicates with the primary exhaust passageway. The sound enhancement assembly includes a sound enhancement device tuned to amplify exhaust sounds of a predetermined frequency and a sound duct downstream of the sound enhancement device that transmits the amplified exhaust sounds to an area outside the engine compartment. The sound enhancement device isolates the sound duct from the exhaust gas. A method for modifying sounds produced by an exhaust system of the internal combustion engine is also disclosed.

An intake manifold is connected to a cylinder of an engine, and extends backward from the cylinder. A throttle body is attached to the intake manifold. As seen in a plan view of an outboard motor, the throttle body is disposed backward of a head cover, while being disposed inward of a lateral end of the intake manifold in a right-and-left direction of the outboard motor.

An air-cooled engine generator usable in an enclosed and relatively small indoor space includes an engine including a crank shaft on which a generator and a fan are provided. An outside cover includes a discharge aperture which discharges cooling air generated by the fan, and covers the engine, the generator, the fan, and a cooling section. The cooling section includes a mixing chamber where a coolant introduced from the outside and exhaust gas discharged from an exhaust pipe of the engine mix with each other, and an outer circumferential surface which is cooled by the coolant that is introduced into the mixing chamber. The exhaust gas is mixed with and cooled by the coolant in the mixing chamber while the cooling air which is supposed to be discharged out of the air-cooled engine generator is cooled by the outer circumferential surface of the cooling section.

An outboard motor includes an engine, a fan driven by the engine to discharge air surrounding the engine, and a cowl housing the engine and the fan. The cowl includes a top cowl that is disposed above the engine and includes an exhaust pathway for exhaust to flow from the fan, and an exhaust port connected to the exhaust pathway and located on the top cowl. The exhaust port opens in a forward direction of the outboard motor.

A marine drive includes an engine; an exhaust conduit that conveys exhaust gases from the engine to an idle relief outlet on the marine drive, wherein the idle relief outlet discharges the exhaust gases to atmosphere when the marine drive is operated at an idle speed; and an idle relief muffler having a muffler inlet that receives the exhaust gases from the exhaust conduit, a muffler outlet that discharges the exhaust gases to the idle relief exhaust outlet, and a drain for draining water from the idle relief muffler. The muffler inlet conveys exhaust gases into the idle relief muffler in a direction that is oriented away from the muffler outlet and away from the drain, such that water in the exhaust gases is encouraged to separate from the exhaust gases and then drain from the idle relief muffler via the drain.