KFX450 backfiring

[ish416]

My 450 just suddenly developed an urge to backfire every time I let off of the throttle.

My KFX is completely stock and never been messed with, never been wrecked.

I have never had any issues with the quad up until this point. I can smell unburned gas in the exhaust.

I have checked all fuses and connections, not sure what else to do.

Anyone else have or heard of this issue?

check your header and your carb boots. sounds like a air leak somewhere.

[the Z Man]

Try tightening the exhaust flange at the head..