The February Dirtbike actually had an interesting article in it. They had Dr. D hisself doing a de-smog on an 08 WR450. It was the usual binocular removal, YZ throttle stop, grey wire cut and a Dr. D pipe with a quiet insert. He used data acquistion techology with a lambda exhaust sensor to do the jetting none of which I have a clue about. His results were a 162 main, a NCVQ#4 needle and a 48 pilot. The stock leak jet was used and he had to adjust the accelerator pump was adjust 1/2 turn in from stock.