Abstract: A watercraft includes an engine output control device that can adjust the maximum output of the engine. The output device can be constructed of mechanical devices for adjusting the relationship between the movement of a throttle lever and a throttle valve, an electronic device for proportionally controlling the position of throttle valves in relation to the movement of the throttle lever, are other devices for controlling engine speeds in other ways.

Abstract: A watercraft is equipped with an outboard motor and an inboard local area network (LAN) that communicates control signals to the outboard motor. An outboard motor operating device retains the ability to operate the outboard motor even if part of the inboard LAN develops an abnormality. In particular, a control signal that controls the outboard motor and a conditional information signal that indicates a condition of the watercraft are transmitted by independent cables that are mutually separated. Even if the cable for transmitting the conditional information signal or equipment connected to the cable develops an abnormality, transmission of the control signal for controlling the outboard motor is not hindered since the control signal is on the other cable, which is not affected by the abnormality. The conditional information signals are processed to generate and display return-to-port warnings based on the watercraft conditions and other operator issued constraints.

Abstract: A management system for watercrafts includes a network. A server is connected to the network. A plurality of terminal computers which belong to customers, dealers and watercraft builders join the network. The server manages warranty condition data of each watercraft. The server collects usage status data regarding each watercraft. The server also determines whether the data are different from the data previously collected. The server further establishes the warranty condition data of each watercrafts based upon the determination.

Abstract: A diagnostic system is provided for a watercraft that is propelled by an outboard drive. Sensors can detect conditions of components related to at least the operation of the outboard drive. The diagnostic system can leave inside and outside computers. The inside computer is placed in the watercraft, while the outside computer is placed out of the watercraft. The outside computer is installed with a program to provide the inside computer with an instruction signal to start a diagnosis on the components. The inside computer is installed with a program to provide sensors with a commencement signal to start checking the components, to require the sensors to provide a detection signal, to collect detection signals, and to provide the outside computer with a result of the checking based upon the detection signals. The program of the outside computer additionally controls a monitor of the outside computer to indicate the conditions of the components based upon the result of the checking.

Abstract: An outboard motor engine includes a feedback control system for controlling the air/fuel ratio of the air/fuel mixture combusted within the engine. The control system can be configured to vary the target output value of a combustion condition sensor in accordance with at least one engine operation characteristic, for example, but without limitation, engine speed or throttle position.

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 outboard motor includes the direct fuel injection system. The outboard motor also includes an ECU that monitors various engine operating conditions and controls various engine operating parameters that are at least partially dependent on the positioning of the transmission. In instances in which the transmission is positioned in a neutral location, the load is decreased and therefore the ECU outputs one set of parameters. In similar low-speed operations, when the transmission is placed in a drive arrangement, the ECU outputs a second set of parameters due to the increased load. Several control routines are disclosed which facilitate low-speed operation, over-rev limiting, and engine warm-up.

Abstract: A diagnostic system is provided to aid a technician or engineer in diagnosing an internal combustion engine. The diagnostic system comprises an electronic control unit that is operatively coupled to a data storage device and to one or more engine sensors. The electronic control unit is configured to collect data from the one or more engine sensors and to store that data in the data storage device. A computer is selectively coupled to the data storage device. The computer program is configured to display specific sets of data stored in the data storage device in various formats.

Abstract: A diagnostic system is provided for aiding a technician or engineer in verifying that a combustion condition sensor provided with an engine is operating properly. The diagnostic system can be used to diagnose the operation of an oxygen sensor included with such an engine. The diagnostic system is configured to sample output voltages of the combustion condition sensor and compare such voltages with predetermined reference voltages.

Abstract: An outboard motor has a fuel injected internal combustion engine operating on either a two-cycle or four-cycle principle. In some embodiments, the engine is directly injected while in others it is indirectly injected. The engine features one of a number of methods for reducing the temperature of injector drivers. The methods include sensing the temperature of the injector drivers and decreasing the engine speed if the temperature exceeds a predetermined temperature. Another method involves sensing the duration of a high-speed, high-load operating condition and slowing the engine speed if the duration exceeds a predetermined time period. Yet another method involves activating a cooling fan if the temperature of the injector drivers exceeds a predetermined temperature and activating a warning device if the temperature does not decrease with the fan operating.

Abstract: A direct injection system and control methodology for two-cycle crankcase compression engines wherein the injection timing is advanced from those normally utilized to avoid the incomplete combustion that results from the prior art method. The injection timing is advanced so that it occurs while the exhaust port is still open but it is timed in such a way that the injected fuel will not be swept out of the exhaust port before the exhaust port closes and so that the fuel will vaporize adequately to be completely burned. The initiation of injection timing is adjusted in response to in combustion chamber air velocity determined by certain parameters such as engine speed and intake air flow.

Abstract: A fuel filter for an internal combustion engine suitable for detecting water accumulated therein. The fuel filter has a holder that is mounted on the engine and holds a filter body. A vessel is detachably affixed to the holder. There is a space between the end of the filter body and the bottom of the vessel. An inlet and outlet are provided for inducing fuel into and discharging it from the vessel. The inlet and outlet are connected relative to each other through the filter body for admitting flow of the fuel. In one feature of this invention, a water detection mechanism is placed under the filter body in the vessel. In another feature of this invention, the vessel is made of a transparent material. In a further feature, the holder is mounted on the engine via a damping member.

Abstract: An outboard motor comprises an engine contained within an engine compartment formed within a power head of the motor. The engine includes a generator having a stator and a rotor. The stator is cooled by a cooling component to reduce the operating temperature of the stator. The cooling component generally comprises a heat transfer plate or cooling jacket that is positioned adjacent to at least a portion of the stator to usher heat build-up away from the stator portion of the generator. The cooling jacket may be in fluid communication with other cooling jackets or may be a discrete system that is separate and distinct from other cooling systems of the motor.

Abstract: Several embodiments of V-type outboard motors having direct cylinder injection using electronic fuel injectors driven by a solenoid driver. The solenoid driver is mounted in the otherwise void area between the cylinder banks of the engine. The solenoid driver is also cooled so as to provide long life and good operation. The cooling can be either by air or water or both. Mounting the solenoid driver in the valley between the cylinder banks also permits shortening of the conduits from the solenoid driver to the solenoids of the injector valves for their operation.

Abstract: A fuel injection control strategy and system for engines for maintaining good performance under normal running conditions and also for providing cylinder engine speed slow-down under abnormal conditions without necessitating cylinder skipping except in extreme cases. This control is obtained primarily by retarding injection timing and/or reducing injection duration. Adjustment in spark timing may also be incorporated along with this routine.

Abstract: An engine idle and speed control arrangement incorporating a butterfly-type throttle valve. The throttle valve is disposed so that it is at a relatively small angle to a plane containing the throttle valve axis and extending perpendicular to the direction of air flow through the induction passage. The peripheral edge of the throttle valve is configured so as to avoid binding. Bypass idle air flow is provided around the throttle valve as to provide substantially the entire idle air speed requirements of the engine. This arrangement permits better idle control since the idle air-flow changes will be more uniform in response to given angular changes in the position of the throttle valve.

Abstract: A fuel injection control strategy and system for engines for maintaining good performance under normal running conditions and also for providing cylinder engine speed slow-down under abnormal conditions by cylinder skipping. Transitional operation between these modes is improved by changing injection timing and/or injection duration of the operating cylinders during this time. Adjustment in spark timing may also be incorporated along with this routine.

Abstract: A feed back control system for a direct injected, two cycle engine having a catalytic exhaust. The injection control is modified if the catalyst overheats to control its temperature.

Abstract: A feed back control system and method for direct injected engines, particularly useful in marine applications to avoid excessive hunting due to the close proximity of the sensor to the fuel injector. Both injection initiation and duration are controlled under most operating conditions. However, under certain conditions such as when only small corrections in the air fuel ratio are required the control is initially maintained by adjusting the injection timing.

Abstract: A feed back control system and method for direct injected engines, particularly useful in marine applications to avoid knocking. Different types of injection control are applied to achieve this depending on the engine running condition when knocking occurs. Both injection initiation and duration are controlled. Injection timing is employed primarily to control knocking under steady state running. Both injection initiation and duration are controlled to avoid knocking under acceleration.