Abstract: An engine includes a cylinder block including a plurality of cylinders disposed along a V-shaped line, a pair of exhaust manifolds disposed inside the V-shaped line, and an exhaust pipe disposed inside the V-shaped line. Each of the pair of exhaust manifolds includes a first passage that includes a plurality of inflow ports into which exhaust gases from the cylinders flow, a collecting portion at which exhaust gases are collected, and an exhaust port from which exhaust gases are discharged. The exhaust pipe includes a connection passage that includes a pair of intermediate inflow ports that are connected to the exhaust ports, at least one intermediate exhaust port from which exhaust gases are discharged. The connection passage is arranged to connect the pair of intermediate inflow ports and the at least one intermediate exhaust port.

Abstract: An engine includes a cylinder block including a plurality of cylinders, an exhaust manifold, and an exhaust pipe. The exhaust manifold includes a first passage and a second passage. The first passage includes a plurality of first inflow ports into which exhaust gases flow from the plurality of cylinders, a first collecting portion that collects exhaust gases that have flowed into the plurality of first inflow ports, and a first exhaust port through which exhaust gases collected by the first collecting portion are discharged. The second passage includes a second inflow port into which exhaust gases flow and a second exhaust port through which exhaust gases that have flowed into the second inflow port are discharged. The exhaust pipe includes a connection passage through which the first exhaust port and the second inflow port are connected together.

Abstract: An outboard motor includes an engine, an exhaust guide, and a catalyst. The engine includes a cylinder and crankshaft. The crankshaft is disposed along a vertical direction. The exhaust guide is arranged to support the engine from below. The catalyst is disposed in an interior of the engine. The engine includes a cylinder body. The cylinder body includes a housing portion arranged to house the catalyst. The cylinder body includes a first exhaust passage that includes an interior of the housing portion. The catalyst is inserted into the housing portion from below and is sandwiched from above and below by the housing portion and the exhaust guide.

Abstract: An outboard motor includes a cooling water passage that guides cooling water to cool an exhaust passage and a cylinder unit. A cooling water intake port draws external cooling water into the cooling water passage. A water pump draws cooling water into the cooling water intake port and supplies the cooling water to the cooling water passage. A thermostat is arranged in the cooling water passage downstream of the catalytic converter and the cylinder unit. A first bypass passage is connected to a first connecting section provided on the cooling water passage. The first connecting section is provided along the cooling water passage at a position farther downstream than the catalytic converter and farther upstream than the thermostat.

Abstract: An exhaust pipe connecting structure includes a first exhaust pipe, a second exhaust pipe, a seal member, and a gasket. The second exhaust pipe is a separate part from the first exhaust pipe. The second exhaust pipe is connected to the first exhaust pipe and defines an exhaust passage together with the first exhaust pipe. The seal member is located between the first exhaust pipe and the second exhaust pipe in a connecting portion where the first exhaust pipe and the second exhaust pipe connect. The gasket is arranged between the seal member and the exhaust passage in the connecting portion where the first exhaust pipe and the second exhaust pipe connect together. The gasket has a heat resistant property.

Abstract: An outboard motor includes an exhaust pipe that includes an outer wall section, an inner wall section, a coolant passage, and a constricted section. The inner wall section is arranged inward of the outer wall section. The coolant passage is arranged between the outer wall section and the inner wall section. The constricted section is configured to constrict a flow cross section of the coolant passage. A catalytic converter is housed in the exhaust pipe. A temperature sensor is installed in the constricted section and measures a temperature of a pipe wall of the exhaust pipe.

Abstract: An outboard motor includes an engine, an exhaust manifold, and a lower exhaust passage. The engine includes a plurality of cylinders, and a plurality of exhaust ports. The cylinders are disposed in-line in a vertical direction. The exhaust ports are respectively connected to the cylinders. The exhaust manifold includes a first passage, a second passage, and a third passage. The first passage is connected to the exhaust ports, and extends in a vertical direction. The second passage is connected to the first passage. The third passage is connected to the first passage below the second passage. The lower exhaust passage is connected to the exhaust manifold, and provides a passage through which exhaust gas is expelled to the outside from the exhaust manifold. One of the second passage and the third passage is connected to the lower exhaust passage.

Abstract: An outboard motor includes an engine, an exhaust guide, and a catalyst. The engine includes a cylinder and crankshaft. The crankshaft is disposed along a vertical direction. The exhaust guide is arranged to support the engine from below. The catalyst is disposed in an interior of the engine. The engine includes a cylinder body. The cylinder body includes a housing portion arranged to house the catalyst. The cylinder body includes a first exhaust passage that includes an interior of the housing portion. The catalyst is inserted into the housing portion from below and is sandwiched from above and below by the housing portion and the exhaust guide.

Abstract: An outboard motor includes an engine, an exhaust guide, and a catalyst. The engine includes a cylinder and crankshaft. The crankshaft is disposed along a vertical direction. The exhaust guide is arranged to support the engine from below. The catalyst is disposed in an interior of the engine. The engine includes a cylinder body. The cylinder body includes a housing portion arranged to house the catalyst. The cylinder body includes a first exhaust passage that includes an interior of the housing portion. The catalyst is inserted into the housing portion from below and is sandwiched from above and below by the housing portion and the exhaust guide.

Abstract: A retaining structure for a honeycomb structure includes a honeycomb structure, a retainer mat, and a housing. The honeycomb structure is a member made of a ceramic material. The retainer mat is in contact with the honeycomb structure and directly retains the honeycomb structure. The housing is in contact with the retainer mat and directly retains the retainer mat. The housing is made of aluminum. The housing includes an inner wall, an outer wall, and a coolant passage. The inner wall is in contact with the retainer mat. The coolant passage is located between the inner wall and the outer wall. An inflow port of the coolant passage is located at one end of the housing. A discharge port of the coolant passage is located at the other end of the housing.

Abstract: An outboard motor includes an engine and a catalyst. The engine includes a cylinder and a cylinder head. The engine includes an exhaust port, a catalyst housing portion, a first exhaust passage, and a passage defining member. The exhaust port is provided in the cylinder head. The catalyst housing portion is provided at a side portion of the cylinder head. The first exhaust passage is arranged to guide exhaust discharged from the exhaust port into an interior of the catalyst housing portion. The passage defining member defines a second exhaust passage. The second exhaust passage is arranged such that exhaust that has passed through the interior of the catalyst housing portion flows into the second exhaust passage. The catalyst is held by the engine in a state in which at least a portion of the catalyst is housed in the interior of the catalyst housing portion.

Abstract: An outboard motor includes an engine, and a top cowling and a bottom cowling that are arranged to cover the engine. A flow-joining pipe is connected to each exhaust port of a plurality of cylinders of the engine. A first exhaust pipe, a second exhaust pipe, and a third exhaust pipe are connected to the flow-joining pipe in sequence. The flow-joining pipe and the first exhaust pipe are connected generally at the same height as a bottommost of the cylinders of the engine. The third exhaust pipe is disposed above a topmost of the cylinders of the engine. A catalyst is disposed in a connecting portion between the first exhaust pipe and the second exhaust pipe so as to be housed in an upper end portion of the first exhaust pipe and in a lower end portion of the second exhaust pipe. The outboard motor is thus able to prevent water from adhering to a catalyst while avoiding any increase in size.

Abstract: An outboard motor includes an engine, and a top cowling and a bottom cowling that are arranged to cover the engine. A flow-joining pipe is connected to each exhaust port of a plurality of cylinders of the engine. A first exhaust pipe, a second exhaust pipe, and a third exhaust pipe are connected to the flow-joining pipe in sequence. The flow-joining pipe and the first exhaust pipe are connected generally at the same height as a bottommost of the cylinders of the engine. The third exhaust pipe is disposed above a topmost of the cylinders of the engine. A catalyst is disposed in a connecting portion between the first exhaust pipe and the second exhaust pipe so as to be housed in an upper end portion of the first exhaust pipe and in a lower end portion of the second exhaust pipe. The outboard motor is thus able to prevent water from adhering to a catalyst while avoiding any increase in size.

Abstract: An engine is disposed in a top cowling. Burned gas produced in the engine is discharged to the outside through a first exhaust pipe, a second exhaust pipe, a third exhaust pipe, exhaust passage, and a exhaust passage. A catalyst is disposed to be housed in the first exhaust pipe and the second exhaust pipe. The first exhaust pipe and the second exhaust pipe are disposed in the top cowling. A fan is provided above the catalyst. As a result of this unique structure, a temperature increase in the cowling is prevented from being caused by heat radiated from the catalyst.

Abstract: An outboard motor includes an engine, and a top cowling and a bottom cowling that are arranged to cover the engine. A flow-joining pipe is connected to each exhaust port of a plurality of cylinders of the engine. A first exhaust pipe, a second exhaust pipe, and a third exhaust pipe are connected to the flow-joining pipe in sequence. The flow-joining pipe and the first exhaust pipe are connected generally at the same height as a bottommost of the cylinders of the engine. The third exhaust pipe is disposed above a topmost of the cylinders of the engine. A catalyst is disposed in a connecting portion between the first exhaust pipe and the second exhaust pipe so as to be housed in an upper end portion of the first exhaust pipe and in a lower end portion of the second exhaust pipe. The outboard motor is thus able to prevent water from adhering to a catalyst while avoiding any increase in size.

Abstract: An outboard motor includes an engine, and a top cowling and a bottom cowling that are arranged to cover the engine. A flow-joining pipe is connected to each exhaust port of a plurality of cylinders of the engine. A first exhaust pipe, a second exhaust pipe, and a third exhaust pipe are connected to the flow-joining pipe in sequence. The flow-joining pipe and the first exhaust pipe are connected generally at the same height as a bottommost of the cylinders of the engine. The third exhaust pipe is disposed above a topmost of the cylinders of the engine. A catalyst is disposed in a connecting portion between the first exhaust pipe and the second exhaust pipe so as to be housed in an upper end portion of the first exhaust pipe and in a lower end portion of the second exhaust pipe. The outboard motor is thus able to prevent water from adhering to a catalyst while avoiding any increase in size.

Abstract: An outboard motor includes an engine, and a top cowling and a bottom cowling that are arranged to cover the engine. A flow-joining pipe is connected to each exhaust port of a plurality of cylinders of the engine. A first exhaust pipe, a second exhaust pipe, and a third exhaust pipe are connected to the flow-joining pipe in sequence. The flow-joining pipe and the first exhaust pipe are connected generally at the same height as a bottommost of the cylinders of the engine. The third exhaust pipe is disposed above a topmost of the cylinders of the engine. A catalyst is disposed in a connecting portion between the first exhaust pipe and the second exhaust pipe so as to be housed in an upper end portion of the first exhaust pipe and in a lower end portion of the second exhaust pipe. The outboard motor is thus able to prevent water from adhering to a catalyst while avoiding any increase in size.

Abstract: An outboard motor includes an engine and a catalyst. The engine includes a cylinder and a cylinder head. The engine includes an exhaust port, a catalyst housing portion, a first exhaust passage, and a passage defining member. The exhaust port is provided in the cylinder head. The catalyst housing portion is provided at a side portion of the cylinder head. The first exhaust passage is arranged to guide exhaust discharged from the exhaust port into an interior of the catalyst housing portion. The passage defining member defines a second exhaust passage. The second exhaust passage is arranged such that exhaust that has passed through the interior of the catalyst housing portion flows into the second exhaust passage. The catalyst is held by the engine in a state in which at least a portion of the catalyst is housed in the interior of the catalyst housing portion.

Abstract: An outboard motor includes an engine, an exhaust guide, and a catalyst. The engine includes a cylinder and crankshaft. The crankshaft is disposed along a vertical direction. The exhaust guide is arranged to support the engine from below. The catalyst is disposed in an interior of the engine. The engine includes a cylinder body. The cylinder body includes a housing portion arranged to house—the catalyst. The cylinder body includes a first exhaust passage that includes an interior of the housing portion. The catalyst is inserted into the housing portion from below and is sandwiched from above and below by the housing portion and the exhaust guide.

Abstract: An outboard motor includes an engine, and a top cowling and a bottom cowling that are arranged to cover the engine. A flow-joining pipe is connected to each exhaust port of a plurality of cylinders of the engine. A first exhaust pipe, a second exhaust pipe, and a third exhaust pipe are connected to the flow-joining pipe in sequence. The flow-joining pipe and the first exhaust pipe are connected generally at the same height as a bottommost of the cylinders of the engine. The third exhaust pipe is disposed above a topmost of the cylinders of the engine. A catalyst is disposed in a connecting portion between the first exhaust pipe and the second exhaust pipe so as to be housed in an upper end portion of the first exhaust pipe and in a lower end portion of the second exhaust pipe. The outboard motor is thus able to prevent water from adhering to a catalyst while avoiding any increase in size.