Abstract: An operation device for a water-jet propulsion watercraft includes a first rotational shaft and a second rotational shaft. A first link can be rotatable about the first rotational shaft and a second link can be rotatable about the second rotational shaft. A bridging link can be configured to be capable of moving in parallel. A rotational end of the first link and a rotational end of the second link can be coupled such that an imaginary straight line connecting the rotational end to the first rotational shaft is parallel to an imaginary straight line connecting the rotational end to the second rotational shaft. A holding section can be provided on the bridging link to be held and operated by an operator.

Abstract: A throttle valve opening control device for a watercraft engine includes a control section for controlling a valve drive section that drives the throttle valve based upon a signal from a remote controller operating position detecting means. The control section determines whether the operating position is in a trolling range or in a propelling range by the signal from the remote controller operating position detecting means. When the control section determines that the operating position is in the trolling range, the control section adjusts the throttle valve opening by an amount, relative to an operational amount of the remote controller, smaller than when the operating position is in the propelling range.

Abstract: A steering system for a small boat can include an outboard motor mounted to a hull, a steering wheel operated by a boat operator for steering the boat, a steering angle sensor for detecting a steering angle of the steering wheel, a steering device for moving the outboard motor relative to the hull in response to the steering angle of the steering wheel, and a controller for determining a target steering angle to be achieved by the steering device using the steering angle and steering characteristics. The steering characteristics are determined in response to running conditions.

Abstract: A boat has a propulsion unit and a steering system. The steering system includes a steering device actuated by an electric actuator. A steering wheel operated by an operator is electrically connected to the actuator. Detectors collect data regarding one or more of operation status of the steering wheel, running status of the boat, status of the propulsion unit(s), status of the electric actuator, and the like. Based upon such collected data, a current for powering the electric actuator may be selectively increased to provide increased torque to ensure excellent steering response even in changing.

Abstract: In an engine rotation control device, a remote control operation device is provided with a remote control side ECU and an engine side ECU so that an outboard motor can be remotely controlled. The remote control side ECU and the engine side ECU periodically communicate a control signal. A gauge includes a slow-speed operation section that changes the engine rotational speed during slow-speed cruising. The slow-speed operation section outputs a change command signal to change the engine rotational speed, and a rotational speed change signal generated by a signal output section based on the change command signal is transmitted to the engine side ECU as a periodic control signal. A reset section of the remote control side ECU resets the rotational speed change signal to an initial state in response to a request from a reset request section.

Abstract: In a boat propulsion apparatus including an engine control device for controlling operation of an engine, the engine control device includes a first ID storage and a second ID storage, a first ID is stored in the first ID storage beforehand, and the engine control device is communicably connected to a controller of a remote control device over a network. A signal containing a second ID is received from the controller when the engine control device and the controller are connected to the network for the first time and is stored in the second ID storage. Thus, maintenance and management of the engine are easy, and also it is possible to prevent a mischievous operation or theft of the boat propulsion apparatus.

Abstract: A boat propulsion apparatus is constructed such that an operation mode can be switched to a reverse mode and an amount of an output can be set by an easy operation without a complicated structure and further in which a main body of the propulsion apparatus can be locked to a hull. The boat propulsion apparatus is provided with a main body and a locking mechanism. The main body of the propulsion apparatus is provided with an electric motor, a throttle grip, a potentiometer arranged to detect an indication by the throttle grip, a first controller arranged to control an operation mode and an output of the electric motor depending on an output of the potentiometer, and second controller arranged to control the locking mechanism depending on an indication provided by the throttle grip.

Abstract: A swivel bracket of an outboard motor pivots about an axis of a tilt shaft disposed at a front end of the bracket unit and extending horizontally in a vertical plane to adjust a tilt angle and a trim angle of the outboard motor. A steering system for the outboard motor includes a pivotal gear attached to the swivel shaft, a drive mechanism driving the pivotal gear, and an electric motor providing drive force to the drive mechanism. Preferably these steering system components are positioned between the swivel bracket and an engine cowling of the outboard motor.

Abstract: A boat propulsion unit controller includes a switch arranged to switch between a long intake duct and a short intake duct for drawing air into an engine of a boat propulsion unit, a motor-operated driver arranged to drive the switch, a duct length switching position sensor arranged to detect the position of the switch at the time of switching the duct length, a fuel supply arranged to supply fuel to the engine, a sensor failure detector arranged to detect failure of the duct length switching position sensor based on its output, and a controller arranged to compensate the fuel supply rate based on the position of the switch detected at the time of duct length switchover. A controller, when the duct length switching position sensor fails, takes the action of switching to the long intake duct and compensates the fuel supply rate using a sensor output quasi value corresponding to the time of switchover to the long intake duct.

Abstract: A boat is capable of preventing shocks on gears in meshing engagement with each other and an abrupt movement thereof when a remote control shift lever is quickly rotated to reverse from a cruising mode. A control microcomputer is arranged to control the operation of a shift actuator based on the displacement of a remote control shift lever for remotely switching between forward, neutral, and reverse positions.

Abstract: A clutch mechanism of an outboard motor includes a forward gear and a reverse gear that are always driven in opposite directions by a drive shaft driven by a drive system, and a dog gear disposed around the output shaft. The forward gear, the reverse gear, and the dog gear are provided with a plurality of engaging projections and engaging recesses that can be engaged with each other, with the dog gear being engaged with either the forward gear or with the reverse gear by forceably moving the dog gear toward one side in the axial direction. A drive shaft has a drive gear and is driven by the drive system generating a maximum output power of about 300 ps or more, the forward gear and the reverse gear have input gears respectively which are always engaged with the drive gear, and the engaging projections and the engaging recesses are located radially inside of the input gears and disposed at least seven in a row along a circumference thereof.

Abstract: A mounting structure for cables for a boat propulsion unit that enables easy insertion of cables into a pass-through hole, as well as highly reliable water-sealing is provided in a bottom cowling of the boat propulsion unit. The cables are inserted in through-holes in a rubber grommet by opening up a slit in the rubber grommet, and then inserting the rubber grommet in a pass-through hole in the port section. The rubber grommet is fit into the pass-through hole in the pressurized condition to water-seal the pass-through hole. The pass-through hole is molded integrally with the bottom cowling. A retaining plate is wrapped around the rubber grommet to prevent the slit from opening up, and the grommet is accommodated in the pass-through hole together with the retainer plate. Then, the retainer plate is fastened to the port section by mounting bolts. Thus, the rubber grommet is fixed within the pass-through hole, and provides water-sealing by filling the gap around the cables within the pass-through hole.

Abstract: An outboard motor includes a bracket assembly that has a swivel bracket carrying a drive unit for pivotal movement about a steering axis that extends generally vertically. The swivel bracket has a tubular section that extends generally vertically. The drive unit has a steering member that includes a steering shaft section extending through the tubular section and defining the steering axis. The steering shaft section has top and bottom portions out of the tubular section. The steering shaft section further has an upper portion below the top portion within the tubular section, and a lower portion above the bottom portion within the tubular section. The tubular section has upper, lower and middle bushings. The upper and lower bushings pivotally support the upper and lower portions, respectively. The middle bushing pivotally supports a middle portion of the steering shaft section between the upper and lower portions.

Abstract: An outboard motor can have a case supported by a hull, an internal combustion engine supported on the upper end of the case, an oil pan formed in the case for storing lubricating oil for the internal combustion engine, and a cooling water jacket formed integrally with the oil pan. A cooling water passage for communicating the cooling water jacket with the internal combustion engine is provided. The cooling water jacket can be formed on the bottom of the oil pan. Optionally, a space can be formed between at least a part of the outer wall of the oil pan and the cooling water passage.

Abstract: A parent-child type boat having an electric power generating device, such as a fuel cell. The boat includes a parent boat and at least one child boat which is smaller than the parent boat. The parent boat is equipped with a generating device. The child boat is equipped with a battery and an electric propulsion device. When the child boat is docked with the parent boat and electrically connected thereto, power can be supplied to at least one of the battery and the electric propulsion device of the child boat from the generating device of the parent boat.

Abstract: An electrical unit includes one of a large current relay, a circuit protection fuse, and an operation time display section fixed on a circuit board having an external connector. The electrical unit is incorporated in a case having an opening, and the electrical unit is sealed by a sealing resin which fills the case. An operation time display section sealed in the case extends from the sealing resin at the opening of the case.

Abstract: A multiple node network includes a plurality of terminal nodes. A management node manages the terminal nodes. A bus connects the respective terminal nodes and the management node to one another. The respective terminal nodes and the management node communicate with each other using a frame that includes at least an identifier field and a data field. The data field has a discriminative number. Each terminal node transfers the frame to the management node. A contention between the terminal nodes is arbitrated by comparing the respective identifier fields of the terminal nodes. When the arbitration fails, each terminal node repeatedly transfers the frame to the management node after a delay time that is unique for the particular terminal node and that is calculated based upon the discriminative number in the data field.

Abstract: A control device for plural propulsion units executes a control for synchronization of the engine rotational speed of a target propulsion unit with the engine rotational speed of a reference propulsion unit when one or more specified conditions are satisfied. Once synchronization control has been established, it is only cancelled if one of the specified conditions becomes no longer satisfied for a first prescribed duration or if another of the specified conditions becomes no longer satisfied for a second prescribed duration.

Abstract: An intake system for a supercharged engine can include a blow-off passage provides communication between the upstream side of the throttle valve and the upstream side of a supercharger. A blow-off valve opens and closes the blow-off passage. The blow-off valve can be configured to open and close based upon pressure on the downstream side of the throttle valve. The present intake system can further comprise a first conduit providing communication between the upstream side of the throttle valve and the blow-off valve, a second conduit providing communication between the downstream side of the throttle valve and the blow-off valve, and a solenoid valve for switching between the first and second conduits.

Abstract: A generally Mo-free, ferrite-austenite duplex stainless steel has a ferrite phase area ratio of about 20 to about 60% and a composition containing, in mass %, not more than about 0.08% of C, about 0.5 to about 1.5% of Si, not more than about 1.0% of Mn, about 4.0 to about 8.0% of Ni, about 23 to about 27% of Cr, about 2.0 to about 6.0% of Cu, about 0.05 to about 0.3% of N, and the balance being Fe and generally unavoidable impurities.