Patent ID: 8038489

Claim:
A boat propulsion system comprising: a prime mover arranged to generate a rotational force; a marine propulsion unit having a propeller arranged to be driven by the rotational force of the prime mover to generate a thrust force; a shift position changing mechanism located between the prime mover and the propulsion unit, and arranged to selectively change a shift position among a first shift position, a second shift position in which a rotational direction of the rotational force of the prime mover is reversed and the reversed rotational force is transmitted to the propulsion unit, and a neutral position; a shift position changing mechanism actuator arranged to actuate the shift position changing mechanism; and a control unit arranged to control the shift position changing mechanism actuator; wherein 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 is arranged to inhibit a change of the shift position to the other one of the first shift position and the second shift position until a predetermined time period elapses; the boat propulsion system further comprising: a control lever arranged to change the shift positions; and a shift position command detecting section arranged to detect a position of the control lever and to output a signal indicative that the shift position changing mechanism is to be at a shift position corresponding to the position of the control lever to the control unit so that the control unit controls the shift position changing mechanism actuator to actuate the shift position changing mechanism to the shift position corresponding to the position of the control lever; wherein even if a signal indicative that the shift position changing mechanism is to be at the other one of the first shift position and the second shift position is outputted from the shift position command detecting section after the shift position change to the one of the first shift position and the second shift position from the neutral position and before the predetermined time period elapses, the control unit does not allow the shift position changing mechanism to change the shift position to the other one of the first shift position and the second shift position.