Patent attributes
A propulsion unit can comprise a propeller and an internal combustion engine for driving the propeller. The propulsion unit can include a gear switching device for changing a drive mode of the propulsion unit between a forward drive mode, a reverse drive mode and a neutral mode. A throttle valve can be configured to control an opening of a first intake passage of the engine, and an idle speed control valve can be configured to control an opening of a second intake passage downstream of the first intake passage can also be provided. The propulsion unit can also comprise a control unit for controlling the idle speed control valve, wherein the control unit is configured to bring the engine to a first target rotational speed when the propeller is in the neutral mode, and to a second target rotational speed when the propeller is in the forward or reverse drive mode, wherein the first rotational speed is greater than the second rotational speed.
