I am sure you have all seen these. Pre Oiled filters for $10.00. As usaul, they do not make them for a KX500. Go to
http://readyfilter.com/ and look at products, you will see a place at the bottom that says if you don't see you model listed click here. Lets see if we can get enough hits to entice them to make a filter for the KX500. If we can I may never clean a filter again.