I'm curious about the "air intake silencer" on the left side of my camhead (2010 GSA.) The REPROM gives its name, how to take it off and put it back on, but what is it? It's a fairly large bore rubber tube connecting the airbox to the left cylinder head, located under the main intake. At first I thought it was an exhaust gas return (EGR) valve thingy, like on cars, but there's no similar tube on the right side as far as I can tell. What does it do? How does it work? How does it silence the air intake? There's nothing wrong with mine, I'm just curious about it. What's it for?