Abstract: A marine vessel includes a hull, an operator station having an operator interface configured to receive a mode input and a lever position input, a left propulsion system, a right propulsion system, and a control module. Each of the propulsion systems includes an engine, a transmission, a troll valve configured to adjust clutch slip, a shaft, a shaft speed sensor configured to detect the speed of rotation of the shaft, and a propeller. The control module is configured to receive the mode input and the lever position input from the operator interface, receive signals from the left shaft sensor indicating a left shaft speed, receive signals from the right shaft sensor indicating a right shaft speed, determine if the vessel is operating in a trolling state, and determine if a sync mode is active, based on the mode input. If the sync mode is active and the vessel is in a trolling state, the speed of the left shaft and the right shaft are synchronized.

Abstract: A hybrid propulsion system for a marine vessel is described. The hybrid propulsion system includes a shaft coupled to a propeller, a planetary gear system configured to operate in a first configuration and a second configuration, and a motor-generator. The motor-generator is configured to selectively rotate with and provide torque to the shaft through the planetary gear system in the first configuration and to rotate independently from the shaft in the second configuration. The shaft extends from the propeller through the planetary gear system and the motor-generator to a torque producing device for the marine vessel.

Abstract: A propulsion device for a marine vessel includes an engine and a forward/reverse shifting mechanism. The direction of a propulsive force generated by the propulsion device is changed according to a shift position of the forward/reverse shifting mechanism. The shift position is changeable between a forward position and a reverse position via a neutral position. In response to a command signal based on an operation of a joystick or an operator, the shift position of the forward/reverse shifting mechanism and the engine are controlled. When the shift position of the forward/reverse shifting mechanism is changed from the neutral position to a position corresponding to a direction opposite to a travelling direction of the marine vessel, which is determined based on the speed of the marine vessel, a correction control is performed to increase an output of the engine based on the speed of the marine vessel.

Abstract: A marine vessel maneuvering system includes a controller configured or programmed to perform a shift-out start control to control a shift actuator to immediately start an intermittent operation mode from a shift-out state when an intermittent operation switching control is performed to switch a normal operation mode in which a shift-in state continues to the intermittent operation mode in which the shift-in state and the shift-out state are repeated in a predetermined period of time based on a user's operation.

Abstract: An engine speed control device for a vessel in which a plurality of outboard motors are mounted on a hull, has a control unit that performs control, on the basis of an operation of one switch, so as to set engines of the outboard motors to a synchronous mode in which the engines have an identical engine speed, wherein the control unit determines in advance an engine to serve as a reference among the engines of the outboard motors, and automatically changes the mode to the synchronous mode in which the engine speeds of engines other than the reference engine become equal to the engine speed of the reference engine when all the engines satisfy a condition to transit to the synchronous mode.

Abstract: A marine power system may include an engine arranged to provide mechanical output power for a boat, and a controller coupled to the engine, the controller configured to determine an idle condition of the boat, deactivate the engine based, at least in part, on the idle condition, determine a demand for the mechanical output power for the boat, and activate, using an auxiliary power source, the engine based, at least in part, on the demand. The controller may be configured to determine the demand based, at least in part, on a throttle control for the boat. The controller may be configured to determine the demand based, at least in part, on a position of a mechanical component of the throttle control. The controller may be configured to determine the demand based, at least in part, on a sensor on the throttle control.

Abstract: An outboard motor includes a trolling mode. The outboard motor includes an outboard motor body including a propeller and a drive source, a tiller handle body extending forward from the outboard motor body, a grip handle extending from a front end surface of the tiller handle body and configured to steer the outboard motor body via the tiller handle body, and a trolling switch attached to the tiller handle body and configured to adjust a trolling speed. An operation portion of the trolling switch is attached to a lower front end surface of the tiller handle body, the lower front end surface being located below the grip handle.

Abstract: An outboard motor includes an engine, a generator to generate power by driving of the engine, a driving force transmitter to transmit a driving force from the engine, a propeller shaft to rotate by being switched from a neutral state in which a clutch is disconnected from the driving force transmitter of the engine at idle to a non-neutral state in which the clutch is connected to the driving force transmitter, and a controller configured or programmed to perform a control to reduce a rotation speed of the engine by regeneration of the generator based on a user's switching operation on a shift operator to switch the outboard motor from the neutral state to the non-neutral state, and then connect the clutch to the driving force transmitter while rotating the engine.

Abstract: A shift device for an outboard motor includes a forward gear and a reverse gear; a clutch gear; a shift actuator configured to move between a neutral reference position where the clutch gear is disengaged from the forward gear and the reverse gear and an engagement reference position where the clutch gear is engaged with the forward gear or the reverse gear; and a control device configured to control a movement of the shift actuator. The control device is configured to set an intermediate target position, and to set a speed at which the shift actuator moves from the intermediate target position to the engagement reference position slower than a speed at which the shift actuator moves from the neutral reference position to the intermediate target position.

Abstract: A ship speed control device is provided, which includes a calculator and a throttle command value setter. The calculator calculates a throttle calculation value based on a difference between an actual ship speed and a target ship speed. The throttle command value setter sets, when the actual ship speed is below a first threshold determined based on a given throttle upper limit and the throttle calculation value is at or above the throttle upper limit, a throttle command value to the throttle upper limit.

Abstract: Example double-blown wing vertical takeoff and landing aircraft are disclosed. An example apparatus includes a wing having a leading edge and a trailing edge, a mounting rib having a first end and a second end, the mounting rib coupled to the wing, the first end forward of the leading edge, the second end aft of the trailing edge, the mounting rib including: a first rotor having a first propeller, the first rotor coupled to the first end of the mounting rib below the leading edge, the first propeller having a first axis of rotation, and a second rotor having a second propeller, the second rotor coupled to the second end of the mounting rib above the trailing edge, the second propeller having a second axis of rotation substantially perpendicular to the first axis of rotation.

Abstract: A first method of protecting an engine and a transmission of a marine vessel during gear shifts and a second method of programming one or more Shift Protection Sequences (SPS) are disclosed. The first method includes receiving a Shift Request (SR) and activating a SPS from among a plurality of enabled SPS. The second method includes configuring a Shift Protection Type (SPT); enabling and configuring a plurality of required and SPS variables; and, optionally, enabling and configuring a plurality of optional SPS variables. The SPT may be a Basic Shift Protection (BSP), which includes time-based SPS; or the SPT may be an Advanced Shift Protection (ASP), which includes alternate time-based and operating-variable based SPS. The SPS of the ASP may be incrementally programmed and added to the BSP.

Abstract: A drive source switching system for a marine propulsion device includes a first drive source, a second drive source, a propeller shaft, a first driving member, a second driving member, a first driven member, and a second driven member that are movable in an axial direction of the propeller shaft, and a controller. The first driven member transmits a drive force generated by the first drive source to the propeller shaft when engaged with the first driving member. The second driven member transmits a drive force generated by the second drive source to the propeller shaft when engaged with the second driving member. When the controller moves the first driven member that is not engaged with the first driving member toward the first driving member, the controller moves the first driven member back when the first driven member fails to be engaged with the first driving member.

Abstract: There is provided a ship propulsion machine including: a drive shaft; a drive gear fixed to the drive shaft; a front gear meshed with the drive gear; a rear gear meshed with the drive gear; a rear propeller provided on an inner propeller shaft; a front propeller provided on an outer propeller shaft; a casing having a gear chamber; a second bearing that supports a front end side of the outer propeller shaft at a rear portion of the casing; a third bearing that supports the inner propeller shaft and the outer propeller shaft in a manner rotatable with respect to each other. The third bearing is disposed on an inner peripheral side of a shaft portion of the rear gear, and the second bearing is disposed on an outer peripheral side of the shaft portion of the rear gear.

Abstract: A marine propulsion system includes a marine propulsion device, a battery, and a controller. The marine propulsion device includes a propeller shaft, an engine, and an electric motor. The marine propulsion device transmits mechanical power from at least one of the engine and the electric motor to the propeller shaft. The battery supplies electric power to the electric motor. The controller controls the marine propulsion device such that the marine propulsion device is switchable among drive modes including a first drive mode and a second drive mode. In the first drive mode, mechanical power is transmitted from only the engine to the propeller shaft. In the second drive mode, mechanical power is transmitted from only the electric motor to the propeller shaft when the engine is in an idling state.

Abstract: A controller of a boat maneuvering control system for a boat is configured or programmed to perform a control to switch from controlling a propulsion device based on a first operation signal that includes error information, to controlling a propulsive force of the propulsion device based on a second operation signal different from the first operation signal upon acquiring the error information.

Abstract: A method for controlling a speed of a propeller of a marine propulsion device during launch of a marine vessel comprises receiving a command to initiate an enhanced launch feature of the marine vessel. The method includes increasing a speed of an engine of the marine propulsion device in response to the enhanced launch feature command. While the engine speed increases, the method includes commanding a first amount of engagement of a forward gear controlling torque transfer from an output shaft of the engine to an input shaft of the propeller. After the engine speed reaches a predetermined threshold, the method includes commanding a second, greater amount of engagement of the forward gear controlling torque transfer from the engine output shaft to the propeller input shaft.

Abstract: A method of mass spectrometry is disclosed comprising focusing electromagnetic radiation into a region of a liquid sample 3 below a surface of the liquid sample so as to generate one or more bubbles 4. The one or more bubbles 4 rise to the surface of the liquid whereupon one or more droplets of liquid 6 are emitted from the surface of the liquid sample. The method further comprises directing the one or more emitted droplets 6 towards an inlet of a mass spectrometer 8.

Abstract: A marine outboard motor is provided with a gear casing, a propeller shaft rotatable within the gear casing about a propeller shaft axis, a drive shaft having a drive gear, a clutch mechanism for selectively engaging the drive gear with the propeller shaft and a shift mechanism configured to operate the clutch mechanism. The shift mechanism comprises a support shaft which is fixed relative to the gear casing and which extends along or parallel with the propeller shaft axis, a shift shuttle which is slidable along the support shaft and is connected to a clutch member of the clutch mechanism, a shift finger pivotally mounted on the support shaft, and a shift rod coupled to the shift finger by a releasable coupling. The shift finger is configured to move the shift shuttle along the support shaft to operate the clutch member.

Abstract: A ship maneuvering system includes first and second propulsion devices, a shift actuator, and a controller. The shift actuator switches a shift state of each of the propulsion devices. The controller causes the shift actuator of one of the first and second propulsion devices to execute intermittent control during low-speed navigation of the ship. The intermittent control intermittently switches the shift state to a shift-in state and a shift-out state.

Abstract: A ship including: an out-drive unit that exerts a propulsion force on a ship hull by power from an engine; a detection device for detecting a current position, a bow direction, and a moving speed of the ship hull; a shift lever that changes magnitude and direction of an output from the out-drive unit; a lever sensor that detects a manipulation position of the shift lever; and a ship steering control device that is connected to the out-drive unit, the detection device, and the lever sensor. The ship steering control device acquires the operating status of the out-drive unit and the detection results obtained by the detection device and the lever sensor and controls the out-drive unit based on the detection results. The ship steering control device performs a dynamic positioning control when the shift lever is in the positioning position.

Abstract: A stroke sensor includes: a shaft that extends in an axial line direction; a detected body that is fixed to the shaft; a housing that extends along the shaft, that houses the shaft, and that supports the shaft slidably in the axial line direction; and a detection body that detects a movement amount of the detected body which moves in accordance with sliding of the shaft, wherein the shaft includes a plurality of shaft members that are connected to each other in the axial line direction and that are formed of metal, and a slide part that is in contact with an inner wall of the housing and that slides so as to regulate a movement of the shaft in a direction that is crossed with the axial line is provided on each of the plurality of shaft members.

Abstract: A trim-tilt device includes a first electric motor electrically connected to a power source and tilts an outboard motor body in an up-and-down direction. A steering device includes a second electric motor electrically connected to the power source. The steering device turns the outboard motor body in a right-and-left direction. A fuel pump is electrically connected to the power source, and supplies fuel to an engine. A controller limits an inrush current into the first electric motor using a PWM control for a predetermined period of time from a starting time point of an input current into the first electric motor.

Abstract: Optical system comprising a motor, an optical element, an optical detector, and a linkage that connects operation of the motor to movement of the optical element and the optical detector relative to one another. The linkage may include a shaft and a drive element that operatively connects the shaft to another part of the linkage. In some embodiments, the drive element may include a clamp having a base and a retainer that compressively secure the drive element to the shaft by engagement of a cylindrical surface region of the shaft with the base and engagement of a flat surface region of the shaft with the retainer. In some embodiments, the drive element may include a collar secured to the shaft with a fastener disposed in threaded engagement with a transverse hole defined by the shaft.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine, a transmission and a low-speed cruise controller controlling a rotational speed of the propeller to make the boat cruise at low speed, the low-speed cruise controller outputs an increase/decrease command of the propeller rotational speed in response to an operator's manipulation, and change the gear position from the second speed to the first speed when the decrease command is outputted under a condition where the gear position is in the second speed and an engine speed is equal to or lower than a predetermined speed. With this, it becomes possible to decrease the propeller rotational speed to the maximum extent, thereby making a boat cruise at very low speed.

Abstract: A transmission is for an outboard marine engine. The transmission comprises a rotatable input shaft that is rotated by an internal combustion engine, a rotatable output shaft that powers a propulsor, a forward gear that causes forward rotation of the output shaft and propulsor, a reverse gear that causes reverse rotation of the output shaft and propulsor, a clutch that is movable between a forward clutch position wherein the forward gear causes the forward rotation of the output shaft and propulsor and a reverse clutch position wherein the reverse gear causes the reverse rotation of the output shaft and propulsor, and an internal ring gear that couples the output shaft to one of the forward gear and the reverse gear.

Abstract: A start control device (20) for an outboard motor (40) has: a determination unit (64) determining whether or not an emergency switch (31) is on when a first switch is operated by a boat operator; a start instruction unit (65) instructing a start of the outboard motor (40) when the determination unit (64) determines that the emergency switch (31) is not on; and a stop instruction unit (66) instructing a stop of a supply of electric power to the outboard motor (40) when the determination unit (64) determines that the emergency switch (31) is on. It is possible to make a state where the electric power is supplied to the outboard motor (40) shift to a state where the supply of electric power to the outboard motor (40) is stopped without starting the outboard motor (40).

Abstract: Systems and methods are for controlling shift in a marine propulsion device. A shift sensor outputs a position signal representing a current position of a shift linkage. A control circuit is programmed to identify an impending shift change when the position signal reaches a first threshold and an actual shift change when the position signal reaches a second threshold. The control circuit is programmed to enact a shift interrupt control strategy that facilitates the actual shift change when the position signal reaches the first threshold, and to actively modify the first threshold as a change in operation of the marine propulsion device occurs.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine to power a propeller, and a transmission being selectively changeable in gear position to establish speeds including a first speed and a second speed and transmitting power of the engine to the propeller with a gear ratio determined by established speed, it is determined whether acceleration is instructed to the engine when the second speed is established and whether a preset condition is met, and operation of the transmission is controlled to change the gear position from the second speed to the first speed when the acceleration is determined to be instructed and the preset condition is met, thereby improving the acceleration performance of immediately after the acceleration is started.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine and transmission, it is configured to determine whether acceleration is instructed to the engine by an operator when the gear position is the second speed, detect a slip ratio of a propeller based on theoretical velocity and actual velocity of a boat, control a throttle opening to suppress increase in the slip ratio when the acceleration is determined to be instructed, and change the gear position from the second speed to the first speed when the slip ratio is equal to or less than a first predetermined value and the change amount of the slip ratio is equal to or less than a prescribed value. With this, it becomes possible to appropriately control operation of the engine and the transmission during acceleration, thereby improving the acceleration performance of immediately after acceleration start.

Abstract: In a control apparatus for an outboard motor having an internal combustion engine and a transmission adapted to establish speeds including first and second speeds and transmit an engine output to a propeller with an established speed, it is configured to determine whether acceleration is instructed to the engine by an operator when the second speed is established; detect an engine speed; detect a navigation acceleration indicative of a change amount of navigation speed per predetermined time; change the gear position from the second speed to the first speed when the acceleration is determined to be instructed; and change the gear position from the first speed to the second speed when the engine speed is at or above a predetermined speed and the navigation acceleration is at or below a predetermined value after the gear position is changed to the first speed.

Abstract: In an apparatus for controlling operation of an outboard motor having an engine to power a propeller, a transmission being selectively changeable in gear position to establish speeds including a first speed and second speed and transmitting power of the engine to the propeller with a gear ratio determined by established speed, and a trim angle regulation mechanism regulating a trim angle through trim-up/down operation, the transmission is controlled to change the gear position from the second speed to the first speed when the second speed is selected and a throttle opening change amount is at or above a predetermined value; and the trim angle regulation mechanism is operated to start the trim-up operation based on engine speed. With this, the transmission can be appropriately controlled to suppress the decrease in boat speed caused by change of gear position, thereby mitigating an unnatural feel given to the operator.

Abstract: An engine control strategy for a marine vessel propulsion system receives a request for a gear from among plural transmission gears, determines an engine speed for the requested transmission gear shift, adjusts the engine to the determined speed for a predetermined amount of time, and prevents the requested transmission gear shift from occurring for the predetermined amount of time while maintaining the engine at the predetermined speed. After the predetermined amount of time elapses, the requested shift is allowed to occur.

Abstract: A marine propulsion device includes an engine, a propeller, a drive shaft, an exhaust path, a water intrusion detecting portion and a recording portion. The drive shaft is configured to transmit driving force from the engine to the propeller. The exhaust path allows exhaust air from the engine to pass therethrough. The water intrusion detecting portion is configured to detect a water intrusion potential indicating a possibility of water intrusion into the engine through the exhaust path. The recording portion is configured to record a detection result of the water intrusion detecting portion.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine to power a propeller, and a transmission being selectively changeable in gear position to establish speeds including a first speed and a second speed and transmitting power of the engine to the propeller with a gear ratio determined by established speed, engine speed is detected, it is determined whether acceleration is instructed when the second speed is established, and operation of the transmission is controlled to change the gear position from the second speed to the first speed when the acceleration is determined to be instructed, and then change back the gear position from the first speed to the second speed based on the detected engine speed, thereby enabling to control the transmission optimally.

Abstract: A boat propelling system capable of reducing electric power consumption includes an outboard engine main body, a swivel bracket arranged to allow the outboard engine main body to pivot in a right-left direction with respect to a hull, an electric motor arranged in the swivel bracket to pivot the outboard engine main body in the right-left direction, a transmission mechanism arranged in the swivel bracket to transmit a driving force of the electric motor to the outboard engine main body, a locking clutch arranged to lock the transmission mechanism so that the outboard engine main body will not be pivoted in the right-left direction by an external force acting on the outboard engine main body, a steering section arranged to steer the outboard engine main body, a steering angle sensor arranged to detect a steering angle of the steering section, a pivot sensor arranged to detect an actual pivot angle of the outboard engine main body, and an ECU arranged and programmed to control the electric motor based on a resu

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine to power a propeller, and a transmission selectively changeable in gear position to establish speeds including at least a first speed and a second speed and transmitting power of the engine to the propeller with a gear ratio determined by established speed, it is configured to determine whether the transmission is in a reverse position, and control operation of the transmission to change the gear position from the second speed to the first speed when the second speed is selected and the transmission is determined to be in the reverse position. With this, it becomes possible to prevent the thrust of the boat from decreasing.

Abstract: In a hybrid type marine propulsion device including a main engine and a motor, low fuel consumption is realized by a compact configuration and highly efficient drive control. A marine propulsion device includes a clutch 7 provided on an input shaft 6 of a main engine, a horizontal input/output shaft 8 connected to the clutch, a vertical shaft 11 connected to the input/output shaft through an upper bevel gear 9, a horizontal propeller shaft 13 connected to a lower end of the vertical shaft through a lower bevel gear 12, and a propeller 14 at the other end side of the propeller shaft, in which the propeller is revolved around the vertical shaft to set a propulsion direction, wherein a motor generator 20 is mounted on a floor 3, and connected directly to the other end side of the input/output shaft. In a low rotation region, motor propulsion is performed, and in a high rotation region, hybrid propulsion in which the main engine is assisted by the motor is performed.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine to power a propeller and a transmission being selectively changeable in gear position to establish speeds including a first speed and a second speed and transmitting power of the engine to the propeller with a gear ratio determined by established speed, a change amount of throttle opening and a change amount of manifold absolute pressure of the engine are detected, and operation of the transmission is controlled to change the gear position from the second speed to the first speed based on the change amounts of the throttle opening and manifold absolute pressure, thereby enabling to appropriately control the operation of the transmission to suppress the decrease in boat speed even when the resistance of water flow acting on a boat during cruising is increased due to influence of a wave, etc.

Abstract: A control device, in particular for a boat drive, which comprises a control drive, a reduction gear system (8, 11, 15/17) and a control element (2) that can be pivoted through a steering angle. The reduction gear system comprises a multi-stage toothed gear transmission (8, 11, 15/17) with a toothed wheel (10) on the drive input side, and the control drive comprises two servomotors (6) which drive the toothed wheel (10) simultaneously but whose driving action are slightly opposed to one another.

Abstract: Propulsion systems for marine vessels comprise an internal combustion engine rotating a driveshaft; an electric motor; a transmission selectively connecting the rotating driveshaft to a propulsor via a rotating gear; and a control circuit controlling the electric motor to slow rotation of the driveshaft and gear when a shift into the gear is requested.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine, a transmission, and a trim angle regulation mechanism, where operation of the transmission is controlled to change the gear position from a second speed to a first speed when detected throttle change amount not less than a first predetermined value and operation of the trim angle regulation mechanism is controlled to start the trim-up operation such that the trim angle converges to a predetermined angle, the operation of the trim angle regulation mechanism is controlled such that the trim angle is decreased based on the detected rudder angle when steering of the outboard motor is started, thereby enabling to appropriately prevent cavitation caused by steering of the outboard motor, so that the boat can be smoothly turned.

Abstract: In an apparatus for controlling operation of an outboard motor having an internal combustion engine, transmission and trim angle regulation mechanism, it is configured to change a gear position to the first speed when the gear position is in the second speed and a throttle opening change amount is at or above a predetermined value, start trim-up operation when the engine speed is at or above a first predetermined speed after the gear position is changed to the first speed, change the gear position from the first speed to the second speed when the engine speed is at or above a second predetermined speed after the trim-up operation is started, and stop the trim-up operation after the gear position is changed to the second speed. It can mitigate a deceleration feel generated when the gear position is changed upon the completion of the acceleration and prevent the pitching occurrence.

Abstract: A boat propelling system capable of determining operation accuracy of a transmission mechanism includes an outboard engine main body, a swivel bracket arranged to allow the outboard engine main body to pivot in a right-left direction with respect to a hull, an electric motor provided in the swivel bracket to pivot the outboard engine main body in the right-left direction, a pivot sensor provided in the electric motor to detect a pivot angle of a motor shaft, a transmission mechanism provided in the swivel bracket to transmit a driving force of the electric motor to the outboard engine main body, a pivot sensor arranged to detect an actual pivot angle of the outboard engine main body, and an Electronic Control Unit arranged and programmed to control an operation of the boat propelling system.

Abstract: A boat propulsion system includes a power source, a propulsion section, a shift position switching mechanism arranged to switch among a first shift position, a second shift position, and a neutral position, a gear ratio switching mechanism, an actuator, and a control section. When switching is to be performed from the neutral position to the first shift position and the high-speed gear ratio, the control section is arranged to cause the actuator to, maintain the low-speed gear ratio, switch to the first shift position, and then establish the high-speed gear ratio when the current gear ratio of the gear ratio switching mechanism is the low-speed gear ratio, and cause the actuator to establish the low-speed gear ratio before switching to the first shift position, switch to the first shift position, and then establish the high-speed gear ratio when the current gear ratio of the gear ratio switching mechanism is the high-speed gear ratio.

Abstract: The invention relates to a method for improving the propulsion efficiency of vessels. The improvement is obtained by utilizing wave induced variations in propeller inflow, i.e. the speed of water flowing towards the propeller. The wave induced water speed variation is used to calculate the propeller speed in a way so that the propeller speed is optimal with respect to the total propulsion efficiency. The optimal propeller speed is determined by solving an optimization problem formulated as the maximization of the ratio of energy delivered by the propeller and the energy delivered to the propeller. The method may be used for vessels with one or more propellers.

Abstract: A marine propulsion device includes an engine, a propeller, a drive shaft, an exhaust path, a water intrusion detecting portion and a recording portion. The drive shaft is configured to transmit driving force from the engine to the propeller. The exhaust path allows exhaust air from the engine to pass therethrough. The water intrusion detecting portion is configured to detect a water intrusion potential indicating a possibility of water intrusion into the engine through the exhaust path. The recording portion is configured to record a detection result of the water intrusion detecting portion.

Abstract: In an apparatus for controlling operation of an outboard motor mounted on a boat and having a torque converter equipped with a lockup clutch, it is configured to have a clutch controller that controls the lockup clutch to ON when a speed ratio of the torque converter is equal to or greater than a reference value, the clutch controller being configured to determine whether a throttle valve is at about a fully-opened position and to control the lockup clutch to ON when the speed ratio becomes equal to or greater than a predetermined value set smaller than the reference value before the speed ratio reaches the reference value, and the throttle valve is discriminated to be at about the fully-opened position. With this, it becomes possible to reliably make a lockup clutch ON when the acceleration is completed, so that the boat speed can reach the maximum speed.

Abstract: In an apparatus for controlling an outboard motor mounted on a stern of a boat and having an internal combustion engine to power a propeller, a drive shaft that connects the engine and the propeller, a torque converter that is interposed between the engine and the drive shaft and is equipped with a lockup clutch, a water pump connected to the drive shaft to be driven by the drive shaft, and a shift mechanism interposed between the drive shaft and the propeller, comprising a neutral position detector that detects the shift mechanism being set in a neutral position; and a clutch ON unit that makes the lockup clutch ON to increase operation speed of the water pump when it is detected that the shift mechanism is set in the neutral position. With this, it becomes possible to improve cooling performance, thereby preventing a defect such as overheat of the engine.

Abstract: A boat propulsion unit includes a power source, a propeller, a shift position switching mechanism, a control device, and a retention switch. The propeller is driven by the power source to generate propulsive force. The shift position switching mechanism has an input shaft connected to a side of the power source, an output shaft connected to a side of the propeller, and clutches that change a connection state between the input shaft and the output shaft. A shift position of the shift position switching mechanism is switched among forward, neutral, and reverse by engaging and disengaging the clutches. The control device adjusts an engagement force of the clutches. The retention switch is connected to the control device. When the retention switch is turned on by an operator, the control device controls the engagement force of the clutches to retain a hull in a predefined position. The boat propulsion unit provides a boat propulsion unit that can accurately retain a boat at a fixed point.