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: An outboard motor includes a prime mover, a marine propulsion unit having a propeller arranged to be driven by a rotational force of the prime mover to generate a thrust force, a shift position changing mechanism, a shift position changing mechanism actuator, and a control unit arranged to control the shift position changing mechanism actuator. When the shift position is changed to one of the first shift position and the second shift position from the neutral position, the control unit inhibits a change in the shift position to the other one of the first shift position and the second shift position until a predetermined time period elapses. The above arrangement improves the controllability of a boat propulsion system having an electronically controlled shift mechanism.

Abstract: An outboard motor includes a power source, a boat propulsion section, a shift position switching mechanism, a clutch actuator, and a control device. The shift position switching mechanism switches among a first shift position in which a first clutch is engaged and a second clutch is disengaged, a second shift position in which the first clutch is disengaged and the second clutch is engaged, and a neutral position in which both the first clutch and the second clutch are disengaged. When a gear shift is to be made from the first shift position to the second shift position, the control section causes the clutch actuator to gradually increase an engagement force of the second clutch. The outboard motor reduces the load to be applied to the power source and the power transmission mechanism at the time of a gear shift in a boat propulsion system including an electronically controlled shift mechanism.

Abstract: A boat propulsion system includes a power source, a propulsion unit, a propeller rotational speed detection section, a shift mechanism, an actuator, a control lever, a shift position detection section, an accelerator opening detection section, and a control unit. When the control lever is operated such that a shift position is changed from a first shift position to a second shift position, while the absolute value of accelerator opening varying speed becomes equal to or larger than a predetermined value, the control unit enables the actuator to maintain the first shift position until the rotational speed of a propeller becomes equal to or lower than a predetermined rotational speed and then to change to the second shift position. This minimizes a load generated on the power source, the power transmission mechanism, and other components of the boat propulsion system.

Abstract: An outboard motor includes a prime mover, a marine propulsion unit having a propeller arranged to be driven by a rotational force of the prime mover to generate a thrust force, a shift position changing mechanism, a shift position changing mechanism actuator, and a control unit arranged to control the shift position changing mechanism actuator. When the shift position is changed to one of the first shift position and the second shift position from the neutral position, the control unit inhibits a change in the shift position to the other one of the first shift position and the second shift position until a predetermined time period elapses. The above arrangement improves the controllability of a boat propulsion system having an electronically controlled shift mechanism.

Abstract: A boat propulsion system includes a power source, a propulsion unit, a propeller rotational speed detection section, a shift mechanism, an actuator, a control lever, a shift position detection section, an accelerator opening detection section, and a control unit. When the control lever is operated such that a shift position is changed from a first shift position to a second shift position, while the absolute value of accelerator opening varying speed becomes equal to or larger than a predetermined value, the control unit enables the actuator to maintain the first shift position until the rotational speed of a propeller becomes equal to or lower than a predetermined rotational speed and then to change to the second shift position. This minimizes a load generated on the power source, the power transmission mechanism, and other components of the boat propulsion 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: An outboard motor includes a power source, a boat propulsion section, a shift position switching mechanism, a clutch actuator, and a control device. The shift position switching mechanism switches among a first shift position in which a first clutch is engaged and a second clutch is disengaged, a second shift position in which the first clutch is disengaged and the second clutch is engaged, and a neutral position in which both the first clutch and the second clutch are disengaged. When a gear shift is to be made from the first shift position to the second shift position, the control section causes the clutch actuator to gradually increase an engagement force of the second clutch. The outboard motor reduces the load to be applied to the power source and the power transmission mechanism at the time of a gear shift in a boat propulsion system including an electronically controlled shift mechanism.

Abstract: An outboard motor includes a cowling enclosing an engine, an ambient air intake defined by the cowling, and an intake passage introducing ambient air taken through the ambient air intake to the engine. The intake passage extends out of and above a top section of the cowling. An inlet portion of the intake passage communicates with the ambient air intake, and an outlet portion thereof communicates with an air inlet leading to a silencer of the engine the air inlet is positioned vertically higher than the intake passage inlet portion.

Abstract: An outboard motor includes an engine having an air intake device. The cowling has an engine room in which the engine is disposed. One or more air intake openings are formed through the cowling. A water separation device is included in the cowling interposed between the air intake opening and the engine room. A first intake passage of the water separator communicates with the ambient air opening. A second intake passage communicates with an upper portion of the first intake passage. If a large flow of water enters the first intake passage through the air opening, such water flows out of the cowling through another opening and/or into a holding chamber formed in the cowling so as not to flow into the second intake passage.

Abstract: An outboard motor includes a cowling enclosing an engine, an ambient air intake defined by the cowling, and an intake passage introducing ambient air taken through the ambient air intake to the engine. The intake passage extends out of and above a top section of the cowling. An inlet portion of the intake passage communicates with the ambient air intake, and an outlet portion thereof communicates with an air inlet leading to a silencer of the engine the air inlet is positioned vertically higher than the intake passage inlet portion.

Abstract: An outboard motor includes an engine having an air intake device. The cowling has an engine room in which the engine is disposed. One or more air intake openings are formed through the cowling. A water separation device is included in the cowling interposed between the air intake opening and the engine room. A first intake passage of the water separator communicates with the ambient air opening. A second intake passage communicates with an upper portion of the first intake passage. If a large flow of water enters the first intake passage through the air opening, such water flows out of the cowling through another opening and/or into a holding chamber formed in the cowling so as not to flow into the second intake passage.

Abstract: An outboard motor includes an engine having an air intake device. A cowling has an internal space in which the engine is disposed and an air intake opening through which ambient air is introduced into the internal space. The internal space defines an air intake passage connecting the air intake opening of the cowling to the air intake device of the engine. An air/water separator is disposed within the air intake passage for separating water from the air. The air/water separator has a relative large volume so as to temporarily hold water from a sudden flow of water that may flow into the cowling air intake. Water accumulated in the separator is drained from the cowling.

Abstract: A crankcase ventilation arrangement for an outboard motor that permits ventilating air and blowby gasses to flow from the crankcase chamber into an induction system of the engine for air purification. In addition, the arrangement is such that oil, which may flow into the ventilating system is separated so that it can return to the crankcase chamber.

Abstract: In a packet transmission method of forming m error correction code packets from n (n>m) data packets including headers, and transmitting the error correction code packets, an n-bit data code portion is formed by reading out pieces of bit information, of the data packets excluding headers, which are located at the same bit position, and sequentially arranging the pieces of bit information. An m-bit error correction code portion is formed by coding information of the data code portion and forming an error correction frame constituted by the data code portion and the error correction code portion. Each bit information of the error correction code portion is assigned as bit information of a corresponding error correction code packet at the same bit position as the bit position of each data packet, from which the bit information is read out.