Abstract: An engine includes an air induction system, a fuel supply system, a lubrication system and a ventilation system. The fuel supply system has a fuel reservoir in which a space for fuel vapors is defined. The lubrication system lubricates a component of the engine with lubricant. The ventilation system couples a crankcase of the engine with the air induction system so as to deliver oil vapors in the crankcase to the air induction system. A fuel vapor passage is arranged to couple the space of the fuel reservoir with the ventilation system.

Abstract: A marine drive has an engine, a propeller and a transmission to switch the propeller between a propulsion position and a non-propulsion position. The engine has a combustion chamber. An air induction system communicates with the combustion chamber through an intake port. An exhaust system communicates with the combustion chamber through an exhaust port. Intake and exhaust valves move between an opening position and a closing position of the intake port and the exhaust port, respectively. Intake and exhaust camshafts actuate the intake and exhaust valves, respectively. A VVT mechanism changes an actuating timing of the intake camshaft at which the camshaft actuates the intake valve. An ECU controls the intake camshaft to set the actuating timing at a generally optimum timing. A transmission position change operation sensor senses that the transmission is under operation and sends a signal to the ECU.

Abstract: An engine includes an air induction system, a fuel supply system, a lubrication system and a ventilation system. The fuel supply system has a fuel reservoir in which a space for fuel vapors is defined. The lubrication system lubricates a component of the engine with lubricant. The ventilation system couples a crankcase of the engine with the air induction system so as to deliver oil vapors in the crankcase to the air induction system. A fuel vapor passage is arranged to couple the space of the fuel reservoir with the ventilation system.

Abstract: An engine for a marine drive has a combustion chamber. An engine body of the engine defines an air intake port communicating with the combustion chamber. An air induction device communicates with the air intake port to introduce air to the combustion chamber through the air intake port. The air induction device includes a throttle valve to regulate an amount of the air. An air intake valve moves between an opening position and a closing position of the intake port. A camshaft actuates the intake valve. A VVT mechanism changes an actuating timing of the camshaft at which the camshaft actuates the intake valve. A control device controls the change mechanism. A throttle position sensor, an intake pressure or other sensors sends respective signals to the control device. The control device determines a sudden acceleration state of the engine based upon at least one of the signals.

Abstract: An outboard motor has an idle speed control in an induction and fuel injection system. The idle speed control controls the rate of flow of air through a bypass passage into the induction system to help improve engine performance. The bypass passage bypasses flow through the throttle body to increase the air flow while the throttle body is either closed or in a wide open position. Of course, the arrangement also can be used to increase the air flow in other orientations of the throttle valve. The bypass passage also is connected to a vent from a vapor separation tank such that vapor from the gas-filled vapor separation tank passes into the bypass air flow and is admitted into the intake system downstream of the throttle valve. The bypass air flow is subdivided between a number of the intake pipes. The bypass arrangement thus advantageously introduces a subdivided amount of ventilation air from the vapor separation tank into each of the plurality of combustion chambers formed within the engine.

Abstract: A fuel supply for an internal combustion engine includes an improved construction for inhibiting vapor from appearing in the fuel supplied to the engine's combustion chamber(s). A fuel injector, as one of fuel supply devices, is provided for supplying fuel to the combustion chamber of the engine. There are a first and second fuel reservoirs. The first fuel reservoir stores fuel and delivers it to the second fuel reservoir through a first fuel supply conduit, while the second fuel reservoir temporarily store the fuel and delivers it to the fuel injector through a second fuel supply conduit. The excess fuel is returned to the second fuel reservoir from the fuel injector through a fuel return conduit. The fuel supply includes a fuel cooling device for cooling the fuel passing through at least one of the conduits. The construction of the fuel supply and the fuel cooling device permits them to be located with the tight confines between the engine and a protective enclosure (e.g., a cowling of an outboard motor).

Abstract: An engine includes an engine body and four pistons reciprocally moveable relative to the engine body. The engine body and the pistons together define four combustion chambers. An air induction system is arranged to introduce air into the combustion chambers. The air induction system includes four intake passages corresponding to the respective combustion chambers. A plenum chamber is coupled with the intake passages. The air is delivered to each combustion chamber from the plenum chamber through each intake passage in due order. The plenum chamber is divided into first and second sub-chambers. The intake passages are categorized into first and second groups. Each group includes two of the intake passages which have discontinuity in the order with each other. The first group is connected with the first sub-chamber. The second group is connected with the second sub-chamber.

Abstract: A four stroke engine having at least two cylinders spaced vertically relative to each other. Each cylinder includes a cylinder body having a cylinder bore extending generally horizontally. Plurality of air intake ducts are provided for connecting a common plenum chamber and respective air intake passages which extends to respective combustion chambers. Each of the air intake ducts has a generally straight section extending generally horizontally and parallel to each other. The distance between the straight sections is less than the distance between the axes of the cylinder bores. Also, in another feature, throttle body means are interposed between duct members, which are upstream components of the air intake ducts, and the intake passages for controlling the flow of air to the combustion chambers.

Abstract: An internal comustion engine has an air induction system that provides an intake passage and an intake silencer, wherein there are a plurality of openings between the silencer and the intake passage. The openings can be selectively closed so as to effectively lengthen or shorten the flow path through the intake passage. upstream portions of the intake passage are disposed within the intake silencer so as to facilitate compactness of the induction system. The openings are closed during low and medium engine speeds, and are opened during high engine speeds.

Abstract: An outboard motor includes a cowling substantially enclosing a four-cycle engine therein. The engine has an air induction device for introducing air to a combustion chamber, and an exhaust system for communicating exhaust products away from the combustion chamber. A pair of camshafts actuate intake and exhaust valves. A variable valve timing (VVT) mechanism is arranged at an upper end of at least one of the camshafts to set the camshaft to an angular position between advanced and delayed angular positions. The cowling includes an air intake, and an engine cover is positioned between the engine and the air intake. The engine cover covers the top and sides of the VVT mechanism so as to protect the VVT mechanism from contact with water that may enter the cowling through the air intake.

Abstract: A fuel supply for an internal combustion engine includes an improved construction for inhibiting vapor from appearing in the fuel supplied to the engine's combustion chamber(s). A fuel injector, as one of fuel supply devices, is provided for supplying fuel to the combustion chamber of the engine. There are a first and second fuel reservoirs. The first fuel reservoir stores fuel and delivers it to the second fuel reservoir through a first fuel supply conduit, while the second fuel reservoir temporarily store the fuel and delivers it to the fuel injector through a second fuel supply conduit. The excess fuel is returned to the second fuel reservoir from the fuel injector through a fuel return conduit. The fuel supply includes a fuel cooling device for cooling the fuel passing through at least one of the conduits. The construction of the fuel supply and the fuel cooling device permits them to be located with the tight confines between the engine and a protective enclosure (e.g.

Abstract: An engine includes an air induction system, a fuel supply system, a lubrication system and a ventilation system. The fuel supply system has a fuel reservoir in which a space for fuel vapors is defined. The lubrication system lubricates a component of the engine with lubricant. The ventilation system couples a crankcase of the engine with the air induction system so as to deliver oil vapors in the crankcase to the air induction system. A fuel vapor passage is arranged to couple the space of the fuel reservoir with the ventilation system.

Abstract: An air induction system for an engine is provided with a flow meter to sense a flow amount of air introduced into a combustion chamber of the engine. The air induction system includes an improved construction that can protect the flow meter from rigorous environment. The construction includes a primary intake passage through which the air flows. A secondary intake passage extends from the primary passage to communicate with the primary passage. At least a portion of the air flows through the secondary passage. A filter is disposed in the secondary passage to filtrate the portion of the air. The flow meter is positioned downstream of the filter in the secondary passage.

Abstract: A four-cycle engine for a marine drive includes an improved construction. The engine has an air induction device for introducing air to a combustion chamber. The air induction device defines an intake port next to the combustion chamber. An intake valve is movable between open and closed positions of the intake port. A valve actuator is journaled on the engine body for rotation to actuate the intake valve at a set angular position. A variable valve timing (VVT) mechanism is arranged to set the valve actuator to the angular position between advanced and delayed angular positions. A dedicated oil pump supplies pressurized oil to an oil control valve, which regulates and controls the VVT mechanism. A lubricant oil pump supplies pressurized oil to an engine lubrication system.

Abstract: An engine includes an air induction system, a fuel supply system, a lubrication system and a ventilation system. The fuel supply system has a fuel reservoir in which a space for fuel vapors is defined. The lubrication system lubricates a component of the engine with lubricant. The ventilation system couples a crankcase of the engine with the air induction system so as to deliver oil vapors in the crankcase to the air induction system. A fuel vapor passage is arranged to couple the space of the fuel reservoir with the ventilation system.

Abstract: An outboard motor has a quieter operating recoil starter arrangement. The recoil starter has a starter drum with a dog clutch arrangement having two dog cam members. The dog cam members rotate between an initial position and an extended position under the influence of a clutch drive member. Specifically, the dog cams each have a portion which engages a starter pulley when a starter rope is pulled. The dog cams are configured to extend minimally into a corresponding slot of the starter pulley when in their extended position. Such configuration results in less chatter when the starter pulley speed exceeds the starter drum speed upon ignition of the engine.

Abstract: An outboard motor includes a cowling substantially enclosing a four-cycle engine therein. The engine has an air induction device for introducing air to a combustion chamber, and an exhaust system for communicating exhaust products away from the combustion chamber. A pair of camshafts actuate intake and exhaust valves. A variable valve timing (VVT) mechanism is arranged at an upper end of at least one of the camshafts to set the camshaft to an angular position between advanced and delayed angular positions. The cowling includes an air intake, and an engine cover is positioned between the engine and the air intake. The engine cover covers the top and sides of the VVT mechanism so as to protect the VVT mechanism from contact with water that may enter the cowling through the air intake.

Abstract: An internal combustion engine for an outboard motor that comprises at least one combustion chamber formed by at least a engine body, a cylinder head assembly and a piston that moves relative to the engine body and the cylinder head assembly. A crankshaft extends in a generally vertical direction and is coupled to the piston such that movement of the piston causes the crankshaft to rotate. A port is in communication with the combustion chamber. A valve is moveable between open and closed positions of the port. A camshaft is journaled for rotation and extends generally parallel to the crankshaft. The camshaft includes at least one cam configured to open and close the valve. A rotor is attached an upper end of the camshaft and is positioned for at least partial rotation within a housing. The rotor defines at least a first space and a second space within said housing. A driven member is coupled to the housing. A drive member is coupled to an upper end of the output shaft.

Abstract: A four stroke engine having at least two cylinders spaced vertically relative to each other. Each cylinder includes a cylinder body having a cylinder bore extending generally horizontally. Plurality of air intake ducts are provided for connecting a common plenum chamber and respective air intake passages which extends to respective combustion chambers. Each of the air intake ducts has a generally straight section extending generally horizontally and parallel to each other. The distance between the straight sections is less than the distance between the axes of the cylinder bores. Also, in another feature, throttle body means are interposed between duct members, which are upstream components of the air intake ducts, and the intake passages for controlling the flow of air to the combustion chambers.

Abstract: An engine of the outboard motor comprises an engine body and a plurality of engine components disposed around the engine body. The cooling system comprises first and second water passages. The first water passage is arranged to cool the engine body. The second water passage branches off from the first water passage upstream the engine body and extends through the engine components. One of the engine components is generally positioned above the engine body. In one arrangement, two of the other engine components are generally positioned on different sides of the engine body relative to one another. In another arrangement, the first and second water passages have separate discharge ports. In a further arrangement, the engine components are made of a metal material. The second water passage at least in part is defined by tubular members made of corrosion-resistant materials and the respective tubular members are at least partially embedded in the respective bodies of the engine components.