Abstract: A remote control device for controlling a propulsion unit of a boat is provided. The remote control device comprises a main body having a shift lever. A housing board is coupled to the main body of the remote control device and extends in a downward direction. The housing board houses a remote control engine control unit that provides an operation output signal to the propulsion unit based on an operation input signal received from the shift lever. In one embodiment, an operator can access the remote control engine control unit from either a starboard side or a port side of the boat. The remote control device can include an additional housing board that is capable of being attached to and detached from the housing board that is coupled to the main body.

Abstract: A boat propulsion unit includes an electric motor, a potentiometer arranged to detect the rotating angle of a throttle grip, a first stop mode sensor, a second stop mode sensor, and a controller including a CPU, and a disconnection and short detecting circuit. If the voltage signal fed by the disconnection and short detecting circuit is out of the specified range, the CPU detects the operation mode designated by the throttle grip based on the switching of the outputs from the first stop mode sensor and the second stop mode sensor. Then, the electric motor is driven in the forward operation mode and with the specified output power when the forward operation mode is designated, whereas, the electric motor is driven in the reverse operation mode and with the specified output power when the reverse operation mode is designated. Using this arrangement, the boat propulsion unit can obtain a minimum required boat operation as intended by the boat operator even when an abnormality has occurred in the controls.

Abstract: A watercraft includes a plurality of outboard motors. Each of the outboard motors has a generator and a rudder deflecting system driven by an electric motor. The outboard motors are turned by the rudder deflecting systems thereby steering the watercraft. Electric power can be supplied from the generators of others of the plurality of outboard motors to the rudder deflecting system of an arbitrary outboard motor among the plurality of the outboard motors. Using this arrangement it is possible to provide a watercraft in which electric power for operation is stably supplied to the rudder deflecting system without increasing the size of the generators.

Abstract: A watercraft includes a plurality of watercraft operating devices arranged to adjust an amount and/or a direction of a propulsive force or a resistance provided to a prescribed position of the watercraft, operation devices arranged to operate the plurality of watercraft operating devices, actuators arranged to actuate the respective watercraft operating devices, and a control unit arranged to control an operation amount of each of the actuators based on an operational state of the operation devices.

Abstract: An engine for an outboard motor is provided that can include a crankcase having a crankcase chamber, a cam chamber, and an oil pan disposed below the crankcase. The engine can also include a crank chamber oil-return passage through which lubricating oil can be returned from the crank chamber to the oil pan. Further, the engine can include a cam chamber oil-return passage through which lubricating oil can be returned from the cam chamber to the oil pan. Finally, the engine can also include a gas passage to provide communication between the crank chamber, the cam chamber, and the oil pan in order to allow passage of blow-by gas without substantial interference with the movement of the lubricating oil.

Abstract: A watercraft propelled by an outboard motor includes an inspection system. The inspection system includes a terminal computer that conducts an inspection of an engine control device and a control unit. The computer includes a program that performs an inspection process that provides the control device with a command signal to start an inspection of the control device and that requests the control device to output a first response signal. The process determines whether the response signal is consistent with a first specified signal. The process provides the control unit with a command signal to start an inspection of the control unit and requests the control unit to output a second response signal. The process determines whether the second response signal is consistent with a second specified signal. The control device controls a throttle actuator and a shift actuator based upon the second response signal and provides the inspection system with an operating signal.

Abstract: A method of steering a watercraft propulsion device mounted to a transom plate and having a steering drive unit which allows the watercraft propulsion device to rotationally move about a swivel shaft. The method can include calculating a steering control amount for the steering drive unit in accordance with the degree of operator's steering wheel displacement and a predetermined steering system response performance, and operating the steering drive unit based on the calculated control physical quantity, in which the predetermined steering system response performance can be, selected from a plurality of plurality of predetermined steering system response performance options.

Abstract: A water cooling system for an outboard motor can include a casing that is configured to be submerged in water at a lower part thereof and to support an internal combustion engine on an upper part thereof. The system can have an exhaust passage that is formed in the casing and through which exhaust gas from the internal combustion engine is inducted from the upper part of the casing toward the lower part, a portion of the exhaust passage between an upstream-side passage and a downstream-side passage being configured as an expansion chamber. Also provided is a cooling water passage extending along the exhaust passage and a drain port that permits water to be discharged into the downstream-side passage after passing through the cooling water passage.

Abstract: An outboard motor engine and a protruding member for use therewith are provided. The outboard motor engine can have a crankshaft whose first end can be connected to a driven member. The protruding member can extend outwardly in the axial direction from a second end of the crankshaft and rotate about an axis with the crankshaft. A flywheel can be fixed on a protruding end side of the protruding member by a tightening member. A drive pulley can be fixed on a base side of the protruding member on the axis. The tightening member can be oriented eccentrically with respect to the drive pulley in the axial direction of the protruding member.

Abstract: A propulsion unit control system is provided for a boat having plural propulsion units provided side by side and electrically connected in association with two adjacent operation levers. The control system synchronizes engine speeds of the respective propulsion units with each other based at least in part on the position of the two operation levers. The control system determines whether certain factors are satisfied before synchronizing engine speeds. The factors include, for example, whether a deviation in angular position between the two operation levers is within a prescribed range. Another factor is whether a deviation between the throttle opening of a reference propulsion unit and a propulsion unit to be synchronized equal to or less than a prescribed value. If the respective deviations are equal to or smaller than a relevant prescribed value, the engine speeds of the respective propulsion units are controlled for synchronization with each other.

Abstract: A fuel supply device for an engine includes a fuel tank positioned such that, at least when the fuel tank is filled with fuel, a first fuel level in the fuel tank is higher than a minimum required second fuel level in a float chamber. A bypass passage that bypasses a fuel pump is provided, and an on-off valve is disposed in the bypass passage. The fuel supply device is capable of improving a starting characteristic of the engine during an off period of the fuel pump without increasing a head difference between the first and second fuel levels.

Abstract: An action control device for a small boat can include a running condition detecting device, a running environment determining device configured to determine a running environment based upon the running condition, and a steering control device configured to set a steering handle operative characteristic in response to the running environment.

Abstract: A lubricant circulating system has a lubricant passage formed in a propeller shaft. The lubricant passage extends axially along the propeller shaft from a bevel gear mechanism to a position proximate to a journal of the propeller shaft. The journal of the propeller shaft is rotatably supported by a bearing. The lubricant passage further extends radially of the propeller shaft and communicates with an area proximate to the bearing. The lubricant circulating system is adapted such that lubricant circulates through the lubricant passage between an upstream opening of the lubricant passage at or around the bevel gear mechanism and a downstream opening of the lubricant passage in the vicinity of the bearing.

Abstract: In a device authentication control method and device, when a connection device is connected to a network mounted on a boat, it is determined whether or not the connection device corresponds to an authentication-free device. If the connection device does not correspond to an authentication-free device, an authenticating action is performed on the connection device. If the connection device does correspond to an authentication-free device, the connection device is exempted from the authenticating action. In this way, when a connection device does not correspond to an authentication-free device, an authenticating action is performed, but when the connection device corresponds to an authentication-free device, the connection device is exempted from an authenticating action. As a result, it is possible to handle specific connection devices as authentication-free.

Abstract: A multiple-cylinder engine for a planing water vehicle includes an operation control device which changes the number of deactivated cylinders step by step in response to an engine speed when the engine speed exceeds a preset speed. The operation control device can have a plurality of cylinder deactivation order maps used for instructing an increment order of cylinders which are deactivated step by step when the engine speed exceeds the preset speed. The operation control device can exchange one of the cylinder deactivation order maps which is currently used for another one of the maps in accordance with an operation state of the engine.

Abstract: A small planing boat can include a multi-cylinder engine, and a propulsion unit driven by the engine, such as a jet pump, for propelling a hull by drawing up and jetting out water. The engine can be configured to change the number of deactivated cylinders in a phased manner corresponding to an engine speed when the engine speed becomes a prescribed speed or more, and can include memory devices for storing a plurality of cylinder deactivation sequence schedules for determining sequences of cylinders that are deactivated and increasing the number of deactivated cylinders in a phased manner. An operation control device configured to deactivate the cylinders of the engine in a phased manner in accordance with the cylinder deactivation sequence schedules stored in the memory devices. The operation control device shifts the cylinder deactivation sequence schedules to be read out from the memory devices to another cylinder deactivation sequence schedule corresponding to an operational state of the engine.

Abstract: In a connection device connected to a network mounted in a boat, a protocol of a connection device connected to a network mounted in a boat is identified based on a communication ID in a certain message transmitted through the network. A device protocol is determined in accordance with the protocol of the network. Data communication in the network is performed in conformity with the device protocol. Accordingly, when the connection device is connected to the network, the connection device automatically identifies a protocol of the network and operates appropriately. Therefore, upward compatibility is maintained and usability is improved.

Abstract: A sealing member can include a radially-working lip which contacts a drive shaft in a radial direction to seal a gap between the drive shaft and the housing in the radial direction, an axially-working lip extending in an axial direction, and a contact member which contacts the axially-working lip to seal the gap between the drive shaft and the housing in the axial direction. The contact member can be fitted to the drive shaft to rotate with the drive shaft.

Abstract: An outboard motor includes a case extending generally vertically and supported on a hull. An engine is supported at an upper end of the case. A propeller is supported by a lower end of the case. A drive shaft is supported within the case for rotation about a generally vertical axis. The driveshaft has an upper end operatively connected to the engine and a lower end operatively connected to the propeller. An upper portion of the case includes an elongate extruded portion having substantially the same cross-sectional shape along its length.

Abstract: A boat can have a propulsion unit connected to a rear surface of a transom plate of a hull. The propulsion unit can have a propeller for producing thrust, a power device for driving the propeller, and a power transmission mechanism for transmitting power from the power device to the propeller. The propulsion unit can also include a braking device configured to exert a generally vertical upward force on the propulsion unit during a braking operation.