See this image:
http://img258.imageshack.us/img258/7696/image35vy0.jpg
(http://img258.imageshack.us/img258/7696/image35vy0.jpg)
The left one is brand new just out of the box.
The right one is used. Just went to a gas station and blew air in it to clean... but looks like it needs change.
I wasn't able to pull up the image for some reason but the paper elements are hard to really clean and should be replaced periodically. Using compressed air works to some degree but if you hit it too hard you can blow a hole in it.
When I went to buy a new air filter I was shocked at how much they were. A Uni foam filter was much cheaper than a stock replacement plus it's reusable and I think it probally filters better than K&N (I have some friends who off road and some of them with K&Ns had some bad things happen) You may be able to find an aftermarket replacement paper ellement for a little bit cheper than a Uni but the Uni is reusable.
You should probally up your jet size a little bit after installing the Uni, since it flows betterthan stock but if you have stock exhaust you may be okay.
You can probally tell I'm a big fan of this filter. I'm always amazed at how much crap comes uot of it when I clean and re-oil it, so I know it works pretty well. It's a great buy in terms of performance, protection, economy, and value.
And no they don't pay me to say that :laugh: but maybee they should
If you change your filter acoording to service manual you'll be fine. The K&N option works great for me. I have one in my VFR, and it's so much better than OEM. But if the UNI does the trick for you, that's great for you :).
nice illustration of the difference between clean and dirty.