'06 crf450x pop in the airbox when i hit the kill switch

is it normal to feel what seems like a strong air bubble popping in the airbox when I hit the kill switch?

Not normal, have you done any work to the bike recently? Timing wise in particular?


Could be tight intake valve - check the valves to spec and see where you're at...

New piston rings, cam chain and intake valves. Got the '06 450x 'bout 9 months ago and that was a first time for each project. One of which remedied the deep pop in the airbox. It was weird. Only did it when I returned from a more than a short ride (at least 30-45min) when I hit the kill switch. Now it seems my only prob. is back-firing any time I quickly let off the throttle. If I slowly ease off it I can avoid about 5 or 6 pops. My plug has quite a bit of that white powdery look to it. This indicates that its runnin' lean right? Thanks for the response fellas.

It sounds like you may need to adjust your fuel air screw. 



Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now