Thermal air valve?

[Bravo12]

I have a 2000 2 stroke 150 hp. On the starboard head is a valve that should have two small rubber lines attached. Mine has one of the barbed fitting broken off so only one line attached that goes to the carbs. It was like this when I bought the boat. I believe this valve effects the idle when the engine is cold. My question is if I get a new valve, where does the other line attach and does it make a difference in the order they are attached to the valve? Thanks for any help.