Abstract: In fuel supply system for an engine in which a discharge port in a fuel pump driven by the engine to draw up fuel in a fuel tank is connected to an inlet port which is provided in a fuel reservoir and which is controlled in opening and closing by a float valve so that the fuel in the fuel reservoir is supplied to the engine, a second discharge port is provided in the fuel pump, and a second inlet port without a float valve is provided in the fuel reservoir. The second discharge port and the second inlet port are connected to each other through a control valve opened during starting of the engine. Thus, when the engine is started, fuel vapor generated in a pump chamber in the fuel pump can be discharged to the fuel reservoir having an air vent, to normalize the function of the fuel pump, leading to an enhancement in hot startability of the engine.

Abstract: A system detecting leakage of an internal combustion engine having a secondary air passage, bypassing a throttle valve, at an air intake pipe connecting to the intake manifold and a secondary air control valve which regulates opening of the secondary air passage. In the system, when the changes in the absolute manifold pressure and the atmospheric pressure before and after the engine starts rotation, are small, it is determined that the intake manifold may possibly leak and should be monitored. Specifically, the opening of the secondary air passage is changed and the changes in the pressure, etc., before and after the opening is changed, are calculated and based thereon, it is determined whether the intake manifold, in fact, leaks. With this, it becomes possible to detect intake manifold leakage accurately with a simple configuration.

Abstract: An oil pressure switch failure detection system for an outboard motor, having a first oil pressure switch which generates an ON signal indicating that the oil pressure is less than or equal to a first predetermined oil pressure and a second oil pressure switch which generates an ON signal indicating that the oil pressure is less than or equal to a second predetermined oil pressure which is set higher than the first predetermined oil pressure. In the system, by discriminating whether the generated signals of the first and second oil pressure switches are equal to be expected signals expected under operating conditions of the engine, it is determined whether at least one of the first and second oil pressure switches fails. With this, it become possible to detect failure of the first and second oil pressure switches, accurately.

Abstract: In fuel rail/fuel conduit connecting structure in an engine for an outboard engine system, a first connecting bore opens into an end face of a fuel rail, and a second connecting bore opens into an end face of a terminal member having a connecting pipe portion which is projectingly provided on one side thereof and to which an end of the fuel conduit is connected. One of halves of a joint collar is fitted to an inner peripheral surface of the first connecting bore with a first seal member interposed therebetween, and the other half of the joint collar is fitted to an inner peripheral surface of the second connecting bore with a second seal member interposed therebetween. Thus, it is possible to connect the fuel rails and the fuel conduits to each other, while providing reduction in number of parts and number of assembling steps for the connecting structure and moreover, the connecting structure is excellent in corrosion resistance.

Abstract: An outboard motor auxiliary fuel tank/fuel pump assembly includes an auxiliary fuel tank disposed in an engine compartment and a fuel pump joined to one side of the auxiliary fuel tank for supplying fuel stored within the auxiliary fuel tank to fuel injection valves of an engine. A float of a float valve provided within the auxiliary fuel tank is supported in the auxiliary fuel tank via a pivot shaft that is parallel to a tilt shaft of an outboard motor. First and second mounting bosses on which the fuel pump can be mounted are formed on the right side face and the front end face of the auxiliary fuel tank.

Abstract: An idling speed control system for an outboard motor mounted on a boat and equipped with an internal combustion engine, whose output is connected to a propeller through a clutch, having secondary air supplier that supplies secondary air. In the system, a difference of preceding and present current command values each indicative of a desired secondary air supply amount is comparing with a predetermined value when the clutch is changed, and the current command value is increased or decreased by a predetermined correction amount when the difference is greater than the predetermined value. With this, it can surely improve the control stability and suppress the overshooting or undershooting of engine speed due to the load change when the clutch is changed, thereby enabling to eliminate or reducing the shock to be felt by the operator and improving the feeling of the operator.

Abstract: An oil pressure warning system for an outboard motor for detecting and alarming an abnormal oil pressure of an internal combustion engine, the system including a first oil pressure switch which generates an ON signal when the oil pressure is less than or equal to a first predetermined oil pressure, and a second oil pressure switch which generates an ON signal the oil pressure is less than or equal to a second predetermined oil pressure set higher than the first predetermined oil pressure. The abnormality of oil pressure is detected and alarmed based on the ON signal of the switches. The first and second predetermined oil pressures are determined based on an oil pressure characteristic of a (possible) maximum oil temperature (under which the engine has been warmed up) set relative to the engine speed, thereby ensuring to detect and alarm the abnormality of oil pressure under any engine speed and any oil temperature.

Abstract: An intake system in a V-type 4-stroke engine for an outboard engine system is provided. A crankshaft of the engine is disposed vertically, and heads of left and right banks are disposed to face rearwards. The engine is covered with an engine hood. In the intake system, an intake air inlet is provided in an upper portion of a longitudinally flat intake air dispensing box disposed between the left and right banks and a rear wall of the engine hood, and leads to an intake passageway in a throttle body. The inside of the intake air dispensing box is divided by a partition wall into first and second dispensing chambers communicating with the intake air inlet and extending longitudinally. An on-off valve is mounted on the partition wall and is capable of bringing the first and second dispensing chambers into and out of communication with each other. Intake ports are provided in the left and right banks to communicate with the first and second dispensing chambers, respectively.

Abstract: An idling speed control system for an outboard motor mounted on a boat and equipped with an internal combustion engine, whose output is connected to a propeller through a clutch, having secondary air supplier that supplies secondary air. In the system, the engine start-state as to whether the engine has been started is determined and the clutch position is detected and based thereon, the desired idling speed and the desired secondary air supply amount is determined through learning control. With this, the system can therefore accurately determine the desired idling speed and the desired secondary air supply amount and achieve steady idling speed even if load changes owing to a change in clutch position or propeller replacement.

Abstract: A system detecting leakage of an internal combustion engine having a secondary air passage, bypassing a throttle valve, at an air intake pipe connecting to the intake manifold and a secondary air control valve which regulates opening of the secondary air passage. In the system, when the changes in the absolute manifold pressure and the atmospheric pressure before and after the engine starts rotation, are small, it is determined that the intake manifold may possibly leak and should be monitored. Specifically, the opening of the secondary air passage is changed and the changes in the pressure, etc., before and after the opening is changed, are calculated and based thereon, it is determined whether the intake manifold, in fact, leaks. With this, it becomes possible to detect intake manifold leakage accurately with a simple configuration.

Abstract: A structure for fitting a generator stator to an engine is provided which allows generator stators having different shapes to be fitted selectively to a common engine main body. In order to selectively fit a first or second generator stator having different shapes from each other to the outside wall of an engine main body, a plurality of first fitting bosses for bolting the first generator stator and a plurality of second fitting bosses for bolting the second generator stator are provided at different positions on the outside wall.

Abstract: An outboard motor auxiliary fuel tank/fuel pump assembly includes an auxiliary fuel tank disposed in an engine compartment and a fuel pump joined to one side of the auxiliary fuel tank for supplying fuel stored within the auxiliary fuel tank to fuel injection valves of an engine. A float of a float valve provided within the auxiliary fuel tank is supported in the auxiliary fuel tank via a pivot shaft that is parallel to a tilt shaft of an outboard motor. First and second mounting bosses on which the fuel pump can be mounted are formed on the right side face and the front end face of the auxiliary fuel tank.

Abstract: An outboard motor equipped with a V-type engine is provided, in which an intake manifold and an auxiliary fuel tank are arranged rationally, thereby contributing to making the engine compartment compact. The outboard motor includes, in an engine compartment formed above a mount case, a V-type engine positioned so that heads of left and right cylinder banks face rearward. An intake manifold is disposed in a hollow between the left and right banks. An auxiliary fuel tank is disposed in an auxiliary equipment installation space that is formed between the left and right banks and the upper face of the mount case.

Abstract: In fuel supply system for an engine in which a discharge port in a fuel pump driven by the engine to draw up fuel in a fuel tank is connected to an inlet port which is provided in a fuel reservoir and which is controlled in opening and closing by a float valve so that the fuel in the fuel reservoir is supplied to the engine, a second discharge port is provided in the fuel pump, and a second inlet port without a float valve is provided in the fuel reservoir. The second discharge port and the second inlet port are connected to each other through a control valve opened during starting of the engine. Thus, when the engine is started, fuel vapor generated in a pump chamber in the fuel pump can be discharged to the fuel reservoir having an air vent, to normalize the function of the fuel pump, leading to an enhancement in hot startability of the engine.

Abstract: In fuel rail/fuel conduit connecting structure in an engine for an outboard engine system, a first connecting bore opens into an end face of a fuel rail, and a second connecting bore opens into an end face of a terminal member having a connecting pipe portion which is projectingly provided on one side thereof and to which an end of the fuel conduit is connected. One of halves of a joint collar is fitted to an inner peripheral surface of the first connecting bore with a first seal member interposed therebetween, and the other half of the joint collar is fitted to an inner peripheral surface of the second connecting bore with a second seal member interposed therebetween. Thus, it is possible to connect the fuel rails and the fuel conduits to each other, while providing reduction in number of parts and number of assembling steps for the connecting structure and moreover, the connecting structure is excellent in corrosion resistance.

Abstract: An engine ignition timing control system for outboard motor having a propeller connected to the engine to be rotated and mounted on a boat such that the boat is propelled forward or backward. The engine is equipped with a decompression mechanism and is started by a recoil starter. In the system, at the time of engine starting, the ignition timing is set to a predetermined crank angle until the detected engine speed exceeds a first prescribed engine speed, while it is set to a value obtained by retrieving a table by at least the detected engine speed after the detected engine speed exceeds the first prescribed engine speed. And, the ignition timing is advanced until the detected engine speed is equal to or greater than a second prescribed value and is then returned to the retrieved value. With this, the engine speed can be reliably increased at starting, without need for a throttle opener or air-fuel ratio enrichment, thereby enhancing engine starting performance.

Abstract: An outboard motor equipped with a V-type engine is provided, in which an intake manifold and an auxiliary fuel tank are arranged rationally, thereby contributing to making the engine compartment compact. The outboard motor includes, in an engine compartment formed above a mount case, a V-type engine positioned so that heads of left and right cylinder banks face rearward. An intake manifold is disposed in a hollow between the left and right banks. An auxiliary fuel tank is disposed in an auxiliary equipment installation space that is formed between the left and right banks and the upper face of the mount case.

Abstract: An intake system in a V-type 4-stroke engine for an outboard engine system is provided. A crankshaft of the engine is disposed vertically, and heads of left and right banks are disposed to face rearwards. The engine is covered with an engine hood. In the intake system, an intake air inlet is provided in an upper portion of a longitudinally flat intake air dispensing box disposed between the left and right banks and a rear wall of the engine hood, and leads to an intake passageway in a throttle body. The inside of the intake air dispensing box is divided by a partition wall into first and second dispensing chambers communicating with the intake air inlet and extending longitudinally. An on-off valve is mounted on the partition wall and is capable of bringing the first and second dispensing chambers into and out of communication with each other. Intake ports are provided in the left and right banks to communicate with the first and second dispensing chambers, respectively.

Abstract: An idling speed control system for an outboard motor mounted on a boat and equipped with an internal combustion engine, whose output is connected to a propeller through a clutch, having secondary air supplier that supplies secondary air. In the system, a difference of preceding and present current command values each indicative of a desired secondary air supply amount is comparing with a predetermined value when the clutch is changed, and the current command value is increased or decreased by a predetermined correction amount when the difference is greater than the predetermined value. With this, it can surely improve the control stability and suppress the overshooting or undershooting of engine speed due to the load change when the clutch is changed, thereby enabling to eliminate or reducing the shock to be felt by the operator and improving the feeling of the operator.

Abstract: An oil pressure switch failure detection system for an outboard motor, having a first oil pressure switch which generates an ON signal indicating that the oil pressure is less than or equal to a first predetermined oil pressure and a second oil pressure switch which generates an ON signal indicating that the oil pressure is less than or equal to a second predetermined oil pressure which is set higher than the first predetermined oil pressure. In the system, by discriminating whether the generated signals of the first and second oil pressure switches are equal to be expected signals expected under operating conditions of the engine, it is determined whether at least one of the first and second oil pressure switches fails. With this, it become possible to detect failure of the first and second oil pressure switches, accurately.