A cowling has first and second cowl portions that enclose a powerhead on a marine drive. A latching assembly is for latching the first and second cowl portions together. The latching assembly has a retainer portion fixed to the first cowl portion and a latching portion fixed to the second cowl portion. The latching portion comprises a latch arm and a bell crank, the latch arm and bell crank being rotatable into and between a latched position in which the latch arm is latched to the retainer portion and an unlatched position in which the latch arm is unlatched from the retainer portion. A novel detent mechanism mechanically retains the latch arm and bell crank in the latched position and alternately in the unlatched position. A pair of bolted connections that fix the first and second cowling portions together and are located on opposite sides of the cowling.

An improved air-cooled aviation engine includes a compact combustion chamber having an intake valve opening, an exhaust valve opening, and a generally elliptical shape. The elliptical shape has a major axis and a minor axis, with the major axis intersecting both the intake valve opening and the exhaust valve opening. In some examples, the major axis is the same length or shorter than a diameter of a cylinder bore of the engine, and the minor axis is smaller than the major axis. Combustion is thus constrained to a smaller area than that of the cylinder bore.

An arrangement of exchangers for marinization of a marine engine, including an engine block with in-line cylinders or cylinders in a V, cooled by a cooling fluid, at least one turbocompressor with a hot chamber connected to an outlet and a cold chamber connected to the cylinders of the engine block, a reverser including a housing and containing oil, wherein the arrangement includes: a radiator hose for supplying cooling water, a turbocompressor exchanger, an engine exchanger, a reverser exchanger, a radiator hose for discharging cooling water toward an outlet of combustion gases, downstream from the hot chamber of the at least one turbocompressor,
with these three exchangers being placed in this order and inserted in the circulation direction of the water between the radiator hose for supplying the cooling water and the radiator hose for discharging this same cooling water.

An arrangement of exchangers for marinization of a marine engine, including an engine block with in-line cylinders or cylinders in a V, cooled by a cooling fluid, at least one turbocompressor with a hot chamber connected to an outlet and a cold chamber connected to the cylinders of the engine block, a reverser including a housing and containing oil, wherein the arrangement includes: a radiator hose for supplying cooling water, a turbocompressor exchanger, an engine exchanger, a reverser exchanger, a radiator hose for discharging cooling water toward an outlet of combustion gases, downstream from the hot chamber of the at least one turbocompressor,
with these three exchangers being placed in this order and inserted in the circulation direction of the water between the radiator hose for supplying the cooling water and the radiator hose for discharging this same cooling water.

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.

A marine propulsion system for a marine vessel has an outboard motor including a cowl covering an internal combustion engine that powers the outboard motor and an accelerometer mounted to the outboard motor. A control module is communicatively connected to the accelerometer. The control module receives information regarding an acceleration of the outboard motor from the accelerometer. The control module uses the information regarding the acceleration of the outboard motor to do at least one of the following: determine an angle of the outboard motor with respect to gravity; determine an amount of oil in an oil sump of the outboard motor; and determine if a reading of the amount of oil in the oil sump is accurate.

A controller performs hydrolock prevention control when an engine is started. The controller determines whether a crankshaft rotates a predetermined number of times upon starting the engine without ignition of the engine. The controller performs the ignition of the engine after the crankshaft rotates a predetermined number of times.

A detection apparatus for detecting a cam angle of a 4-stroke multi-cylinder engine in which explosion intervals are unequal intervals, includes a detection target member configured to rotate in synchronism with a camshaft, and first and second cam angle sensors configured to detect rotation of the detection target member. The detection target member includes a plurality of first detection target portions arranged, at equal pitches, as many as the number of cylinders of the multi-cylinder engine. The second cam angle sensor is arranged while being shifted in the rotation direction with respect to the first cam angle sensor such that any one of detection signals of the plurality of first detection target portions by the first cam angle sensor and the second cam angle sensor is output at a timing corresponding to each explosion interval.

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.

An outboard motor stabilizer of unitary construction has a cylindrical body and an axially oriented cylindrical orifice with an opening at the bottom end of the body. The orifice has a diameter sized to fit onto a tilt rod of an outboard motor and is of a length that is longer than the tilt rod of the outboard motor.