A marine engine has a powerhead, a crankcase and a crankshaft disposed in the crankcase. A cooling system has a cooling passage that conveys cooling water for cooling the crankcase, a pump that pumps the cooling water from a body of water in which the marine engine is operated through the cooling passage, and a valve that controls discharge of the cooling water from the cooling passage.

This oil case of an outboard motor is provided below an engine and stores lubricating oil of the engine. In this method for manufacturing the oil case, the oil case is manufactured so as to comprise: an oil chamber; an introduction path that guides upward cooling supply water drawn in from outside the outboard motor; a delivery path that guides downward cooling discharge water that has cooled the engine; a main exhaust path that guides exhaust gas of the engine downward; and a sub exhaust path that guides exhaust gas during low-speed rotation of the engine. The oil chamber, the introduction path, the delivery path, the main exhaust path and the sub exhaust path form an integral structure.

There is provided a ship propulsion machine that gives a propulsive force to a ship, including: a power source; a propulsion device that converts power of the power source into a propulsive force of the ship; a power transmission mechanism that transmits power of the power source to the propulsion device; a casing that covers the power source and the power transmission mechanism; and a fine dust capturing device. The fine dust capturing device includes: a water intake which is provided in the casing and through which water around the ship propulsion machine is to be taken in, a capturer that captures fine dust contained in water taken in from the water intake, and a water outlet through which water in which the fine dust was captured by the capturer is to be discharged.

A cooling system is for cooling a marine engine having an engine block and a cylinder head, and a supercharger configured to provide charge air for combustion in the marine engine. The cooling system has a charge air cooler configured to cool the charge air prior to combustion in the marine engine. The cooling system is configured to circulate cooling water from a body of water in which the marine engine is operating to the marine engine and then back to the body of water. The cooling system is further configured to convey the cooling water in parallel to the marine engine and the charge air cooler. A sprayer is configured to spray the cooling water into exhaust gas discharged from the marine engine. The cooling system is configured to convey the cooling water in series to the charge air cooler and then to the sprayer.

A marine engine has a powerhead, a crankcase and a crankshaft disposed in the crankcase. A cooling system has a cooling passage that conveys cooling water for cooling the crankcase, a pump that pumps the cooling water from a body of water in which the marine engine is operated through the cooling passage, and a valve that controls discharge of the cooling water from the cooling passage.

A marine engine has a crankcase containing lubricant; an intake plenum for conveying intake air for combustion in the marine engine; and a cooling apparatus located between the crankcase and the intake plenum. The cooling apparatus is configured to cool both the lubricant in the crankcase and the intake air in the intake plenum.

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 vessel propulsion device having a metal component in contact with water. The marine vessel propulsion device includes an anticorrosive anode made of a metal material that is less corrosion-resistant than the metal component, is electrically connected to the metal component, and is disposed in contact with the water contacting the metal component, a primary reference electrode isolated from the metal component and the anticorrosive anode, and disposed in contact with the water contacting the metal component, and a potentiometer that detects a potential difference of the metal component or the anticorrosive anode with respect to the primary reference electrode.

A marine outboard engine includes an internal combustion engine assembly that includes an internal combustion engine, a fuse assembly, a fuel filter, a spark plug, a gearcase including one of a propeller and an impeller, a swivel bracket, and a cowling. The cowling includes a service panel disposed on a first lateral side of the internal combustion engine assembly, and an affixed panel disposed on a second lateral side of the internal combustion engine assembly. The service and affixed panels define a split line therebetween and are removably attached to each other. The fuse assembly, the fuel filter, and the spark plug are mounted to one of the first lateral side and the affixed panel proximate to the split line and are at least in part accessible from the first lateral side when the service panel is detached and removed from the affixed panel.

A system includes an engine defining a water jacket fluidly coupled to a heat exchanger. An exhaust manifold defines an exhaust manifold cooling passage. A pump is fluidly coupled to the water jacket, and to each of the heat exchanger and the exhaust manifold cooling passage. An engine cooling circuit includes the water jacket, the heat exchanger, and the pump. An exhaust cooling circuit is selectively fluidly coupled to the engine cooling circuit. The exhaust cooling circuit includes the water jacket, the exhaust manifold cooling passage, and the pump. A control valve includes an inlet fluidly coupled to a first portion of the water jacket. A first outlet is fluidly coupled to a second portion of the water jacket. A second outlet is fluidly coupled to the exhaust cooling circuit. The control valve is structured to selectively control flow of coolant fluid through the second outlet.