Tried the no airbox lid thing and it ran like a busted **** .Would not idle or accelerate properly.I think they run to lean .

 

Search the posts, there are pictures of the restrictive '09 snorkles and the KDX snorkle. I really don't think you can un-restrict it. I have the Kawasaki part # in my signature for the KDX snorkle I have on mine now. OR, as some say, just remove it or the lid.

 

I just removed the snorkle on my 09. I love the combined sound of the FMF Q muffler and the throatie sound from the air box. Sounds like a Ducati. LOL