I didn't touch the jetting on my old 2007 DRZ. This time with all the hype around the JD Jetting kit I thought I would go ahead and give it a try. One note for other Australian 2009 DRZ400E owners is the actual Main Jet is the exact same one as standard a 165, the only advantage is the new needle which I think has removed some of the initial hesitation but this could have been the working of the Power Now that I fitted at the same time.