I just bought a used 2000 WR400 from Nebraska and as I suspected it needs some jetting and free mod work. You guys all have 426's. but I'm assuming they are close enough that LarryCO's jetting setup will work for me, or at least be close enough for me to have some minor tweaking to do. What do you think? It was mentioned in this thread that a "PAS" can be bought from sudco? What the heck is a PAS? Can I get the rest of the jets from my dealer? I'm going out and buying all these jets as soon as I understand what the hell I'm doing. I like to educate myself first. Also, I saw a couple mods in signatures that I don't understand. What is the ACV mod? What is the BK mod? The only thing my bike has done is the throttle stop removal. I unplugged the exhaust as soon as I got home. With it in, it sounded like my fiance's TTR-125 - pathetic. I'm going to do the gray wire mod and airbox today. I'm going to Moab the last weekend of the month and want to get this thing fired up. Anyone that wants to join is welcome. We always camp within pissin' distance of slickrock, so we can have a morning warm up before the boozers wake up and get ready for the day's ride. We usually have a big hunting tent with a stove for hanging out and mornings, but sleep in our own personals tents. Any jetting adjustments I need to be concerned about for 4K Moab?