I did my 99 500 with a k&n kit and after going on a 45-50 mile ride through various conditions and speeds-I know NOT the best/right way but it was a after thought and shows regular usage-anyway I checked the spark plug and it seems to me its burning the same which is - looking not HOT but pretty lean well thats my opinion. I'm wondering what anyone else has had for luck & conditions after putting one of the kits in? I after reading the directions and following them I ended up with the new needle set @clip#4 position and jet went from a 157.5 down to a 155 these settings are for 0-3000ft--now most of my riding is from 1000-3500ft and I am wondering if I ought to go back to stock jet with k&n needle&setting as being on #4 its "richer" then factory setting ---thats what throws me, leaner on the main and richer with the needle-----Whats your settings at?