Carb'ed bikes, K&N, and motor supposed to sound (video clip)

http://youtu.be/BTSMLQ0PMeQ

So cleaned the K&N's, ran sea foam and now I have a sucking in air sound coming from the motor when I rev it? Normal?

Source: http://www.esportbike.com/forums/showthread.php?t=144802&goto=newpost

Franco Bertoni Juan Bertran Willi Bertsch Paul Berwick Kees Besseling