An engine assembly includes an engine structure and an intake assembly. The engine structure defines a first cylinder, a second cylinder, a first intake port in communication with the first cylinder, and a second intake port in communication with the second cylinder. The intake assembly includes a first throttle valve, a second throttle valve and a boost mechanism. The first throttle valve is in communication with the first and second intake ports. The second throttle valve is in communication with an air source and the first throttle valve and located in a series flow arrangement between the air source and the first throttle valve. The boost mechanism is in communication with the air source and the first throttle valve and located in a series flow arrangement between the air source and the first throttle valve.