I pulled my plug and it was really wet, sooty, and black. I am assuming I am rich. I am going to check for air leaks and then change the main jet. I bought a 150 & 145. I have been reading carb tuning articles and they talk about the "needle" and shimming or moving a clip on it. Is this something I should do also or just switch out the main and do some plug readings. 3000ft elev. very low humidity, ride in 40 to 90 degree temps. All stock bike except K&N

 

Switch out the main and do some plug readings.

 

Well, I finally got around to pulling the carb apart. I bought this bike from a low elevation town somewhere in the 0-500' elev. I took it to my home where I ride 3000-4900' range but mainly in the 3000-3500 range.

The bike is bone stock except a K&N in a stock factory airbox.

So I pull the main and its a 165. I pull the needle jet and the clip is on the bottom (6th) clip (the richest). I pull out the Clymer manual and it calls for 3rd clip on the needle and 2 turns out on the air screw so I make the corrections. The manual calls for a 155 main for 0-3000' feet

So I know I need a leaner main than a 165 so I head down to my polaris dealer. They say because of the K&N I should be running 157.5 to 162.5. I dont get it? Does the K&N let in so much more air to go richer than stock yet running at higher altitudes? Shouldnt I be in the 150 main range?