An internal combustion engine comprising an engine body. A combustion chamber is formed in the engine body and has at least one valve seat. A valve is configured to move between an open position and a closed position of the valve seat. A valve actuator is configured to actuate the valve. A variable valve timing mechanism is configured to change an actuating timing of the valve actuator at which the valve actuator actuates the valve. At least one sensor configured to sense and operational condition of the engine. A control device is configured to determine if the engine is operating in a cruising mode. The control device is also configured to reduce engine speed fluctuations during the cruising mode by adjusting the actuating timing of the valve actuator.