My XR650R came with a K&N air filter. Now if you do not a PC Racing pro seal you have to use grease. This can be a mess when you need to change the filter on the fly hundreds of miles from home. It turns out PC Racing has discontinued:excuseme: making the seal for the BRP. So I just bought a No-toil filter. Now it appears I may need a backfire screen. I really can't tell if the no-toil filter will stay in place with no backing. Any help here it's time to ride. And need to know my air filter is working right before the Honda sucks down a quart of dust.