Four-cycle engine for marine drive

摘要

A four-cycle engine for a marine drive has an air induction device introducing air to a combustion chamber. The air induction device defines an intake port next to the combustion chamber. An intake valve is movable between open and closed positions of the intake port. A valve actuator is journaled on the engine body for rotation to actuate the intake valve at a set angular position. A setting mechanism is arranged to set the valve actuator to the angular position between advanced and delayed angular positions. A sensor is arranged to sense an amount of the air within the induction device. A control system is configured to control the setting mechanism based upon the signal of the sensor. The control system controls the setting mechanism to set the valve actuator to an angular position that is closer to the first angular position than a present angular position when the signal indicates that the amount of the air increases and a change rate of the amount is greater than a preset change rate.