I ride a 400ex is it ok with out the outwears cover? And how do you like your K&N's thanks[img]i/expressions/face-icon-small-smile.gif[/img]

 

I ALWAYS run an outerwears! It take care of the big stuff, so the filter only has to handle the rest. Nice thing about the Outerwears is that it is dry (unlike a foam filter), and the dirt doesn't stick to it.

 

If your keeping the airbox lid on your probably fine without an outerwear - now way I'd run without an outerwear if the lid is removed or modified. Outerewears are cheap though so might as well go ahead and run with it for extra protection. I like my K&N very well.

 

There are no disadvantages to running one, and the advantages are significant!