Patent ID: 8851946

Claim:
An apparatus for controlling operation of an outboard motor mounted on a stern of a boat and having an internal combustion engine to power a propeller through a drive shaft and a propeller shaft, and a transmission that is installed at a location between the drive shaft and the propeller shaft, the transmission being 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, comprising: a throttle lever which opens and closes a throttle valve of the engine upon manipulation by an operator; an acceleration instruction determiner that determines whether acceleration is instructed to the engine by the operator when the gear position is second speed; a slip ratio detector that detects a slip ratio of the propeller based on theoretical velocity and actual velocity of the boat; a throttle opening controller that controls a rate of change of throttle opening of the engine in accordance with characteristics before correcting the throttle opening with respect to the manipulation of the throttle lever by the operator; and a transmission controller that controls the transmission to change the gear position from the second speed to the first speed when the detected slip ratio is equal to or less than a first predetermined value and a change amount of the slip ratio is equal to or less than a prescribed slip ratio change amount while the throttle opening is controlled by the throttle opening controller, wherein the throttle opening controller controls the rate of change of the throttle opening of the engine in accordance with characteristics after correction with respect to the manipulation of the throttle lever by the operator after the acceleration is determined to be instructed, and the characteristics after correction are set to decrease the rate of change of the throttle opening compared to the characteristics before correcting the throttle opening, so that the throttle opening controller controls the rate of change of the throttle opening to suppress an increase in the detected slip ratio after the acceleration is determined to be instructed.