Sounds like flapping in my Airbox?

[Guiness63]

It started the other day. As I accelerate it sounds like there is a flapper valve or something in my airbox. Each gear I hear it, like a valve slapping open and closed rapidly. Smoothes out on the highway. Any suggestions? 09XB12SS

 

[strmvt]

did you do the open airbox mod if so what your hearing is air being sucked into the throttle body

 

[Guiness63]

Nope just stock, for now.

 

[tuneport67ss]

Sounds like you mighthave a miss or a plug that is not quite firing right. Just something to check out. Mine did the same thing earlier this spring when I got it out to ride. I pulled the plugs and cleaned them and then she ran like a sewing machine. It wasnt really a skip, but it was more of a slight miss that I too noticed through the airbox.

 

[Paniller]

A misfire will sound like a cough from the airbox, so I agree that it could be rapid misfiring making that sound. A plug may be on its way out.

 

[Guiness63]

Thanks i'll have to check the plugs out.