In an outboard motor control system, a position of a clutch (moved by an actuator) is memorized as a neutral position when a neutral switch produces an ON signal and the clutch position corresponding to a forward position where the clutch engages with a forward gear or a reverse position where the clutch engages with a reverse gear is determined based on the memorized position. With this, the clutch can be accurately shifted to the positions where the forward, neutral and reverse shift positions are established, thereby preventing shifting errors. Similarly, by memorizing rudder angle sensor outputs when the outboard motor is mechanically stopped by left and right steer stops as maximum leftward or rightward rudder angles, desired values for control purposes when steering the outboard motor to the maximum rudder angles can be determined as values that take the unit-specific properties of the outboard motor into account.