Abstract: An exhaust system is for a marine propulsion device having an internal combustion engine. A catalyst housing has a housing inlet end that receives an exhaust gas flow from the internal combustion engine into the catalyst housing and an opposite, housing outlet end that discharges the exhaust flow out of the catalyst housing. A catalyst is disposed in the catalyst housing. The catalyst has a catalyst inlet end that receives the exhaust gas flow and an opposite, catalyst outlet end that discharges the exhaust gas flow. A catalyst mantel is on an outer periphery of the catalyst. The catalyst mantel has a mantel inlet end and an opposite, mantel outlet end. A radial flange is on at least one of the mantel outlet end and mantel inlet end. A connector mates with an inner diameter of the catalyst housing. The radially extending flange of the catalyst mantel is axially sandwiched between the connector and a radially inner shoulder of the catalyst housing.

Abstract: A marine propulsion device includes an internal combustion engine driving a driveshaft into rotation and a starter-generator motor in a torque transmitting relationship with the driveshaft. The starter-generator motor is alternately operable in a positive torque mode where it is powered by a battery to exert a positive torque on the driveshaft, and in a negative torque mode where it exerts a negative torque on the driveshaft and generates a charge to the battery. A control module is configured to receive an engine RPM, determine an engine RPM drop rate, and determine that the engine RPM drop rate exceeds a threshold drop rate. The starter-generator motor is then operated in a positive torque mode based on the engine RPM drop rate when the engine RPM drop rate exceeds the threshold drop rate.

Abstract: A method of controlling two or more propulsion devices on a marine vessel includes receiving a vessel speed, determining that the vessel speed is below a first vessel speed threshold, receiving an operator thrust demand, and determining that the operator thrust demand is below a first demand threshold. At least one of the two or more propulsion devices is then turned off, and a thrust output of at least one remaining propulsion device is adjusted based on the operator thrust demand.

Abstract: A method for controlling a marine engine for propelling a marine vessel includes receiving user input as a user input device to control acceleration of a marine vessel, detecting a rapid acceleration command based on the user input, and determining an advanced spark timing based on at least one of engine speed and engine load, wherein the advanced spark timing adjusts a base spark time by a spark advance offset. A fuel increase is then determined based on the spark advance offset, and then an increased fuel injection amount is determined by increasing a base fuel injection amount by the fuel increase. Spark and fuel delivery are then controlled for one or more cylinders of the marine engine based on the advanced spark timing and the increased fuel injection amount.

Abstract: An exhaust system is for a marine propulsion device having an internal combustion engine. A catalyst housing has a housing inlet end that receives an exhaust gas flow from the internal combustion engine into the catalyst housing and an opposite, housing outlet end that discharges the exhaust flow out of the catalyst housing. A catalyst is disposed in the catalyst housing. The catalyst has a catalyst inlet end that receives the exhaust gas flow and an opposite, catalyst outlet end that discharges the exhaust gas flow. A catalyst mantel is on an outer periphery of the catalyst. The catalyst mantel has a mantel inlet end and an opposite, mantel outlet end. A radial flange is on at least one of the mantel outlet end and mantel inlet end. A connector mates with an inner diameter of the catalyst housing. The radially extending flange of the catalyst mantel is axially sandwiched between the connector and a radially inner shoulder of the catalyst housing.

Abstract: An exhaust system is for a marine propulsion device having an internal combustion engine. A catalyst housing has a housing inlet end that receives an exhaust gas flow from the internal combustion engine into the catalyst housing and an opposite, housing outlet end that discharges the exhaust flow out of the catalyst housing. A catalyst is disposed in the catalyst housing. The catalyst has a catalyst inlet end that receives the exhaust gas flow and an opposite, catalyst outlet end that discharges the exhaust gas flow. A catalyst mantel is on an outer periphery of the catalyst. The catalyst mantel has a mantel inlet end and an opposite, mantel outlet end. A radial flange is on at least one of the mantel outlet end and mantel inlet end. A connector mates with an inner diameter of the catalyst housing. The radially extending flange of the catalyst mantel is axially sandwiched between the connector and a radially inner shoulder of the catalyst housing.

Abstract: An exhaust manifold is for an internal combustion engine on an outboard marine engine that is configured to power a propulsor to provide a thrust in a longitudinal direction. The exhaust manifold comprises an exhaust runner that transversely and longitudinally rearwardly conveys the exhaust gas from the internal combustion engine, an exhaust log that vertically upwardly conveys the exhaust gas from the exhaust runner, and an exhaust elbow that conveys the exhaust gas from the exhaust log vertically upwardly, longitudinally forwardly, and then vertically downwardly.

Abstract: An exhaust system is for a marine propulsion device having an internal combustion engine. The exhaust system comprises a catalyst housing having a housing inlet end that receives exhaust gas flow from the internal combustion engine and an opposite, housing outlet end that discharges the exhaust gas flow. A catalyst is disposed in the catalyst housing. An outlet collector receives the exhaust gas flow from the catalyst housing. The outlet collector comprises a collector inlet end that is engaged with the housing outlet end. One of the collector inlet end and housing outlet end overlaps with the other of the collector inlet end and housing outlet end at a joint. A seal is disposed at the joint between the collector inlet end and the housing outlet end. The joint is devoid of a cooling water jacket.

Abstract: A marine propulsion device and a method of making a marine propulsion device including an internal combustion engine that discharges exhaust gases. The internal combustion engine has first and second castings. A first exhaust flow passage is in the first casting and a second exhaust flow passage is in the second casting. The second exhaust flow passage has a first and second leg that are transversely oriented to each other. A catalyst is disposed in the second exhaust flow passage and configured to treat the exhaust gases. A flow control element is between the first and second flow passages. The flow control element forms a smooth transition that is devoid of edges such that the exhaust gases flow across and are dispersed by the flow control element before being treated by the catalyst.

Abstract: A marine propulsion device has an internal combustion engine that discharges exhaust gases, a driveshaft housing that is located vertically below the engine, and a catalyst that is sandwiched between opposing castings of the device that face each other at a split-line. The exhaust gases flow through the catalyst parallel to the split-line.

Abstract: An outboard marine propulsion device comprises an internal combustion engine. At least one engine cooling passage conveys cooling water through the internal combustion engine. An exhaust manifold comprises a plurality of exhaust runners and an exhaust log. The plurality of exhaust runners axially conveys exhaust gases from the internal combustion engine to the exhaust log. A cooling jacket on the exhaust manifold comprises an exhaust log cooling jacket that conveys the cooling water along an outer surface of the exhaust log and a plurality of exhaust runner cooling passages that each axially convey the cooling water along an outer surface of a respective one of the plurality of exhaust runners from the exhaust log cooling jacket to the engine cooling passage.

Abstract: A marine drive and marine exhaust pipe include a main exhaust flow chamber and an auxiliary idle relief chamber. The auxiliary idle relief chamber vents exhaust above the surface of the body of water in which the vessel is operating.

Abstract: An anti-ingestion system is provided for a marine drive with a submerged exhaust outlet. An anti-ingestion valve is operated by differential pressure thereacross to a closed condition when the engine is operating in an on state and cooling water is being pumped through a water conduit to an exhaust mixing point, with the anti-ingestion valve blocking passage of cooling water therepast in the noted closed condition. The anti-ingestion valve is operated by differential pressure thereacross to an open condition when the engine is in an off state, and permits passage of air therethrough and communicates atmospheric pressure through the water conduit to the exhaust mixing point to relieve vacuum in the exhaust system.

Abstract: An anti-ingestion system is provided for a marine drive with a submerged exhaust outlet. An anti-ingestion valve is operated by differential pressure thereacross to a closed condition when the engine is operating in an on state and cooling water is being pumped through a water conduit to an exhaust mixing point, with the anti-ingestion valve blocking passage of cooling water therepast in the noted closed condition. The anti-ingestion valve is operated by differential pressure thereacross to an open condition when the engine is in an off state, and permits passage of air therethrough and communicates atmospheric pressure through the water conduit to the exhaust mixing point to relieve vacuum in the exhaust system.