Intake airflow control mechanism for engine

An intake airflow control mechanism for an engine includes a first valve shaft on which valve elements of intake airflow control valves are fitted in such a manner that the valve elements pivot in accordance with the rotation of the first valve shaft; a second valve shaft on which valve elements of intake airflow control valves are fitted in such a manner that the valve elements pivot in accordance with the rotation of the second valve shaft; an actuator that rotates the first valve shaft, a link mechanism that transmits the rotation of the first valve shaft to the second valve shaft, a stopper that stops the rotation of the second valve shaft when the second valve shaft is in a prescribed rotational position, and a sensor that detects the amount by which the first valve shaft is rotated by the actuator.