Abstract: A personal watercraft includes a hull and a jet propulsion unit that propels the hull. An engine powers the jet propulsion unit. The engine includes an air intake system to introduce air to a combustion chamber. The intake system includes a throttle valve to regulate an amount of the air. The throttle valve is moveable generally between a closed position and an open position. A fuel injection system is arranged to spray fuel for combustion in the combustion chamber. The engine also includes an intake pressure sensor, a throttle valve position sensor and an engine speed sensor. A control device is provided to control an amount of the fuel using either a D-j control mode or an &agr;-N control mode. The D-j control mode is based upon a signal from the intake pressure sensor and a signal from the engine speed sensor. The &agr;-N control mode is based upon a signal from a throttle valve position sensor and the signal from the engine speed sensor.

Abstract: An engine includes an electronic controller which samples the pressure in the induction system once per rotation of the crankshaft. The controller is configured to determine the minimum voltage signal output by the pressure sensor. The controller then uses the minimum pressure sensed by the pressure sensor to control the fuel injection of the engine. The controller may include two and/or three dimensional maps for predicting the appropriate timing for sampling the pressure sensor. The engine also includes a smoothing system so as to provide for more accurate sampling of the pressure within the induction system.

Abstract: A watercraft includes a performance mode selector which enables a rider to select normal operation of the watercraft or an economy mode operation. In the economy mode operation, the watercraft either disables cylinders or reduces fuel injection and ignition in order to limit the maximum engine speed obtained by the engine when the throttle lever is fully depressed Additionally, the watercraft can disable cylinders or selectively reduce fuel injection or ignition when an abnormal operating parameter has been detected.

Abstract: A watercraft has a throttle position sensor, an engine speed sensor, and a start switch. The sensors communicate with a controller. The controller can regulate engine speed. The controller regulates or limits the engine to a low speed when the throttle angle is above a predetermined value during startup, and/or when the engine temperature is too low.

Abstract: An internal combustion engine includes at least one combustion chamber formed by at least a first member and a second member that moves relative to the first member. The second member is coupled to an output shaft such that movement of the second member causes the output shaft to rotate. A fuel injection system includes a fuel injector that supplies fuel to the combustion chamber and a fuel pump that supplies fuel to the fuel injector. The fuel injector includes an actuator to regulate an amount of fuel injected by the fuel injector. A main switch has an on position and an off position. A fuel control system includes a controller, which is operatively connected to the actuator, and a sensor, which is arranged to detect rotation of the output shaft. The sensor is adapted to produce a signal that is indicative of rotation of the output shaft and is operatively connected to the controller.

Abstract: An engine idle control system includes an improved construction for changing an aimed idle engine speed, which is preset by the manufacturer therein, in response to various needs of a user. The engine has a main passage having a throttle valve therein and a bypass passage arranged to bypass the throttle valve. The bypass passage supplies an idle air charge to a combustion chamber of the engine when the throttle valve is generally closed and has an adjusting valve therein for adjusting the idle air charge. A control device controls the adjusting valve to reduce a difference between an actual idle speed sensed by an engine speed sensor and an aimed idle speed preset in the control device. The control device includes means for changing the aimed idle speed.

Abstract: An engine includes an engine body and a generator. The engine body has a stator bracket mounted to the cylinder block. The generator incorporates a rotor flywheel and an armature assembly consisting of armature legs. Various metal plates with high magnetic permeability make up the armature legs and are securely fastened in a radial manner to the similar plate made of aluminum. The stacked armature legs surround the crankshaft and are mounted to the stator bracket. The preferred heat conduction path travels from the armature legs through the aluminum plate on onto the stator bracket in order to improve the heat dissipation of the generator.

Abstract: A watercraft has an engine that is controlled to reduce the likelihood of engine stall when the watercraft engine speed is rapidly decreased while the watercraft is in a planing mode. The engine is controlled by a method that detects a rapid engine speed decrease when the watercraft is believed to be in the planing mode. A operational characteristic of the engine is adjusted to increase the engine speed such that, after the engine reaches a stable engine speed, the stable engine speed is higher than a desired idle speed. The operational characteristic can be an advance in ignition timing or an increase in airflow to the engine.

Abstract: The present vehicle data system collects, encodes, transmits, decodes, and displays engine and vehicle operation information. In one mode, an engine control unit of an outboard boat motor receives a plurality of engine and vehicle operation parameters from a plurality of sensors. The engine control unit encodes the plurality of parameters in a single signal and transmits the encoded signal to a display unit over a signal line. The display unit decodes the encoded signal to extract the plurality of parameters and displays the extracted parameters to the vehicle operator.

Abstract: An outboard motor comprises an engine mounted within an engine compartment. The engine comprises an induction system having an induction passage extending between an air intake box to a combustion chamber. A throttle valve is positioned along the passage. A bypass passage communicates with the passage at a location between the throttle valve and the combustion chamber. An adjustable valve controls flow through the bypass passage. The adjustable valve can be closed at a first rate if a transmission of the outboard motor is engaged and at a second rate if the transmission is disengaged.

Abstract: A watercraft has an overturn detector. The detector communicates with a controller. The controller does not act on overturn signals when the watercraft is planing. The controller also monitors the overturn detector for failure. In the event of a failure during engine starting, the engine is allowed to run while the operator is alerted. In the event of a failure during engine operation, the engine is stopped and the operator is alerted if the watercraft is not in planing mode. If the failure during engine operation occurs when the watercraft is in planing mode, the operator is alerted but the engine is not stopped.

Abstract: A fuel injection system for an engine includes an improved construction to inhibit heating of the fuel. A fuel reservoir is arranged to store the fuel therein. A fuel pump is provided for delivering the fuel in the reservoir to a fuel injector which sprays fuel toward a combustion chamber of the engine. The fuel pump is driven by an electric motor that is intermittently powered. In one embodiment, a control device is provided for controlling the duration for which the electric motor is powered. A duty ratio of the duration is preferably determined in response to an amount of the fuel that is required to be sprayed by the fuel injector.

Abstract: A four-cycle engine for a marine drive has an air induction device 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 setting mechanism is arranged to set the valve actuator to the angular position between advanced and delayed angular positions. A sensor is arranged to sense an amount of the air within the induction device. A control system is configured to control the setting mechanism based upon the signal of the sensor. The control system controls the setting mechanism to set the valve actuator to an angular position that is closer to the first angular position than a present angular position when the signal indicates that the amount of the air increases and a change rate of the amount is greater than a preset change rate.

Abstract: An internal combustion engine includes an improved feedback control system and method for operating the engine to provide the desired air/fuel ratio under all running conditions without causing unsettling variations in engine speed and torque as adjustments to the air/fuel ratio are made. The feedback control operates to modify the fuel/air ratio from that achieved by a basic setting that is derived from parameters of engine performance so as to maintain the desired ratio. The control system also adjust the ignition timing while the air and fuel ratio is adjusted toward the desired ratio to maintain generally constant engine speed and torque.

Abstract: The present vehicle data system collects, encodes, transmits, decodes, and displays engine and vehicle operation information. In one mode, an engine control unit of an outboard boat motor receives a plurality of engine and vehicle operation parameters from a plurality of sensors. The engine control unit encodes the plurality of parameters in a single signal and transmits the encoded signal to a display unit over a signal line. The display unit decodes the encoded signal to extract the plurality of parameters and displays the extracted parameters to the vehicle operator.

Abstract: An engine includes an electronic controller which samples the pressure in the induction system once per rotation of the crankshaft. The controller is configured to determine the minimum voltage signal output by the pressure sensor. The controller then uses the minimum pressure sensed by the pressure sensor to control the fuel injection of the engine. The controller may include two and/or three dimensional maps for predicting the appropriate timing for sampling the pressure sensor. Optionally, the controller may include a bottom hold device for holding a minimum value of the signal output from the pressure sensor, thus corresponding to the minimum pressure sensed by the pressure sensor.

Abstract: An outboard motor powers a watercraft and comprises an engine mounted within an engine compartment. The engine comprises an induction system having an induction passage extending between an air intake box to a combustion chamber. A throttle valve is positioned along the passage. A bypass passage communicates with the passage at a location between the throttle valve and the combustion chamber. An adjustable valve controls flow through the bypass passage. The adjustable valve can be closed at a first rate if a the watercraft is traveling at a speed greater than a preset value and at a second rate if the watercraft is traveling at a speed below the preset value.

Abstract: A watercraft engine includes a lubrication system alarm control system which initiates an alarm when lubricant pressure within the lubrication system falls below an acceptable pressure. The alarm system compares lubricant pressure during engine operation with a lower pressure threshold which is determined as a function of engine speed. Thus, partial reductions in lubricant pressure are identified. Additionally, the alarm control system may be configured to emit an alarm if lubricant pressure fluctuates at a rate that is greater than a predetermined pressure fluctuation rate threshold.

Abstract: A fuel and lubricant supply system for an engine of the type utilized to power an outboard motor of a watercraft is disclosed. The system includes a fuel supply and a delivery mechanism for delivering fuel from the supply through a fuel system including at least one charge former. The system also includes a lubricant supply and a delivery mechanism for delivering lubricant from the supply through a lubricant system to at least a portion of the fuel system. A fluid pressure operated check valve is provided along the lubricant system for preventing the flow of fuel into the lubricant system. Preferably, the check valve includes a fluid sensor providing data to a control unit which controls the lubricant delivery mechanism for controlling the volume of lubricant delivered to the fuel system.

Abstract: The present invention is an apparatus and method for detecting an operating condition of an oil pump of the type utilized in an oil supply system for a internal combustion engine. The apparatus includes a sensor for detecting the movement of a piston and/or a check valve of an oil pump. The apparatus preferably includes an engine control for monitoring the sensor over a fixed time interval and determining whether a signal is indicative of a malfunction or abnormality. In accordance with the method, the pump is monitored with the sensor and in the event an abnormality is detected, a warning indicator is activated and/or the engine is shut off.