Abstract: An outboard motor mounted to a hull of a watercraft includes a V-type engine having right and left cylinder banks positioned in a cowling and having a crankshaft generally vertically disposed when the watercraft is under a running condition. A surge tank is disposed in the cowling. Right and left side long intake conduits and right and left side short intake conduits both connect the surge tank to intake ports of respective right and left banks of cylinders. The associated long intake conduits and short intake conduits can be selectively established depending on information about operational conditions of the hull and/or the outboard motor. The outboard motor includes right and left shut-off valves interchanging the long intake conduits and the short intake conduits. Right and left actuators individually actuate the right and left shut-off valves in accordance with information about operational conditions. A control means individually controls operations of the respective actuators.

Abstract: An outboard motor is mounted on a hull and has an engine disposed in an upright position in a cowling so that a crankshaft thereof extends generally vertically during cruising. An embodiment of the motor includes a first surge tank disposed on the opposite side of a cylinder head of the engine with respect to the crankshaft of the engine; long intake pipes that communicate with the first surge tank and an intake port of the engine; second surge tanks disposed between the long intake pipes and the engine for communicating with the first surge tank; short intake pipes provided in the midway of the long intake pipes on the engine side for communicating with the second surge tanks; and on-off valves for opening and closing the short intake pipes.

Abstract: An outboard motor mounted to a hull of a watercraft includes a V-type engine having right and left cylinder banks positioned in a cowling and having a crankshaft generally vertically disposed when the watercraft is under a running condition. A surge tank is disposed in the cowling. Right and left side long intake conduits and right and left side short intake conduits both connect the surge tank to intake ports of respective right and left banks of cylinders. The associated long intake conduits and short intake conduits can be selectively established depending on information about operational conditions of the hull and/or the outboard motor. The outboard motor includes right and left shut-off valves interchanging the long intake conduits and the short intake conduits. Right and left actuators individually actuate the right and left shut-off valves in accordance with information about operational conditions. A control means individually controls operations of the respective actuators.

Abstract: An outboard motor is mounted on a hull and has an engine disposed in an upright position in a cowling so that a crankshaft thereof extends generally vertically during cruising. An embodiment of the motor includes a first surge tank disposed on the opposite side of a cylinder head of the engine with respect to the crankshaft of the engine; long intake pipes that communicate with the first surge tank and an intake port of the engine; second surge tanks disposed between the long intake pipes and the engine for communicating with the first surge tank; short intake pipes provided in the midway of the long intake pipes on the engine side for communicating with the second surge tanks; and on-off valves for opening and closing the short intake pipes.

Abstract: An outboard motor can be mounted on a transom plate of a hull, and can have an engine disposed in an upright position in a cowling so that a crankshaft thereof extends generally vertically during cruising. A surge tank can be located on the hull side of the engine in the cowling, and a mounting portion for an electric component can be provided on a front face of the surge tank.

Abstract: A marine drive has an open loop cooling system for cooling various engine components using water drawn from the body of water in which an associated watercraft is operating. A water inlet of the cooling system has a filter cover which includes a series of apertures through which water can flow. The apertures have a maximum cross-sectional width. After passing through the water inlet, cooling water is pressurized and directed to an engine coolant passage to cool engine components. A pilot water passage branches off of the engine coolant passage and delivers cooling water through peripheral engine components to cool the components. The pilot cooling water is discharged from the marine drive in a pilot water stream that is visible to the operator of the watercraft. No portion of the pilot water passage has a diameter that is less than the maximum dimension of the water inlet filter cover openings.

Abstract: An engine includes an engine body and an air induction system. The engine body includes a cylinder block defining a cylinder bore in which a piston reciprocates. A cylinder head member closes an end of the cylinder bore to define a combustion chamber together with the cylinder bore and the piston. The air induction system is arranged to introduce air into the combustion chamber. The induction system includes a first intake conduit through which the air flows to the combustion chamber. A first plenum chamber unit is disposed upstream of the first intake conduit. A control mechanism is arranged to control an amount of the air flowing through the first intake conduit. The induction system also includes a second intake conduit through which the air flows to the combustion chamber. A second plenum chamber unit is disposed upstream of the second intake conduit. The second intake conduit is coupled with the first intake conduit downstream of the control mechanism.

Abstract: A marine drive comprises an open loop cooling system for cooling various engine components using water drawn from the body of water in which an associated watercraft is operating. A water inlet of the cooling system has a filter cover which includes a series of apertures through which water can flow. The apertures have a maximum cross-sectional width. After passing through the water inlet, cooling water is pressurized and directed to an engine coolant passage to cool engine components. A pilot water passage branches off of the engine coolant passage and delivers cooling water through peripheral engine components to cool the components. The pilot cooling water is discharged from the marine drive in a pilot water stream that is visible to the operator of the watercraft. No portion of the pilot water passage has a diameter that is less than the maximum dimension of the water inlet filter cover openings.

Abstract: An engine includes an engine body and an air induction system. The engine body includes a cylinder block defining a cylinder bore in which a piston reciprocates. A cylinder head member closes an end of the cylinder bore to define a combustion chamber together with the cylinder bore and the piston. The air induction system is arranged to introduce air into the combustion chamber. The induction system includes a first intake conduit through which the air flows to the combustion chamber. A first plenum chamber unit is disposed upstream of the first intake conduit. A control mechanism is arranged to control an amount of the air flowing through the first intake conduit. The induction system also includes a second intake conduit through which the air flows to the combustion chamber. A second plenum chamber unit is disposed upstream of the second intake conduit. The second intake conduit is coupled with the first intake conduit downstream of the control mechanism.

Abstract: An electrical system for an engine of the type utilized to power an outboard motor is disclosed. The engine has a body with a crankshaft rotating therein. At least one fuel injector supplies fuel to the engine for combustion. The electrical system includes an electronic engine control unit for controlling at least the fuel injector based upon one or more sensed conditions. The electrical system also includes at least one sensor for providing data regarding one or more conditions. Preferably, at least an air pressure and intake air temperature sensor are provided. The sensors are mounted to a portion of the engine body adjacent the crankshaft, preferably via a vibration isolated bracket, for improving sensor accuracy and reliability.

Abstract: A fuel injected induction system for a crankcase compression, two-cycle, V-type internal combustion engine includes a plurality of throttle valves corresponding in number to the number of crankcase chamber of the engine. Each throttle valve communicates with a dedicated intake passage that directly communicates with a respective crankcase chamber. At least one fuel injector is positioned within each intake passage in order to form the air/fuel charge delivered to the crankcase chamber. The corresponding number of throttle valves, fuel injectors and crankcase chambers allows for enhanced control over the air-fuel ratio delivered to each of the cylinders, as well as improved consistence of the air-fuel charge delivered to each of the cylinders of the engine.

Abstract: An intermediate drive mechanism allows an alternator to be mounted beneath an engine flywheel on the side of the engine. This location reduces both the girth and height of the engine, thereby reducing the size of the power head of an outboard motor. The intermediate drive mechanism includes a first intermediate pulley, which lies generally at the same level as a drive pulley attached to the engine output shaft. A second intermediate pulley lies beneath the first intermediate pulley and generally at the same level as a driven pulley of the generator. Belts couple the pulleys of the intermediate drive mechanism to the respective drive and driven pulleys. The intermediate pulleys also can move relative to the corresponding pulleys so as to function as a belt tensioner.

Abstract: A fuel system for an outboard motor includes a low-pressure fuel transport subsystem and a high-pressure fuel delivery system. The fuel transport system guides fuel from a fuel tank located in the hull of the watercraft to a fuel tank located with a cowling surrounding the engine. The high-pressure fuel delivery system supplies fuel to a fuel rail that communicates with fuel injectors of the engine's induction system. The induction system communicates with crankcase chambers on a side of the engine opposite of the engine cylinders. The low-pressure fuel transport subsystem is located on a side of the induction system opposite of the high-pressure fuel delivery subsystem. This layout minimizes the flow path length from the fuel tank within the cowling to the fuel rail. It also reduces the girth of the engine and simplifies the arrangement of the fuel hoses of the fuel supply system.

Abstract: A hydraulic tilt and trim mechanism for a marine outboard drive wherein the trim cylinder is provided with a valve element that is positioned responsive and which defines a fluid lock when the piston is in a trimmed down position for providing hydraulic resistance to further trim-down operations so as to minimize noise and wear. A mechanical stop is also provided within the trim cylinder.