My opinion of Yamaha, I'm sad to say, has dropped a notch. Here is what I've experienced so far with my 05' WRF 450: 1) Paid cash from dealer, got home and drooled over my new ride. 2) One week later, followed the manual to the tee and broke it in for just over an hour. Started out idling OK but an hour later would not idle steady. Kind of "surged" between too high and too low idle. Fiddling with the idle adjustment didn't fix the problem......concern sets in. At break in, I had replaced the throttle stop with a YZF unit and snipped the gray wire. Nothing else. I should also mention that the power was decent on accleration with no noticable dead spots 3) changed oil and filter when I got home. 4) Fired it up a few times over the next week to see if rough idle persisted. At initial firing, it idles fine the first minute but as it warms up and I putt around the driveway(couple minutes later) the idle races too high or too low like before. When I chop the throttle, the engine wants to race and not return to low idle without applying the brakes(1st gear) when brakes are applied, it idles down. 5) Since I bought the bike from a Yamaha dealer who is more marine(boat) oriented, I took it to a different dealer who is all bike. They've been good to me in the past and I trust their expertise. I said "for a brand new bike it sure won't idle....somethings not right. Please ride it for 5 minutes and see if you notice what I do. See if you can pinpoint anything." At this point, I mentioned this should be a warranty issue shouldn't it? The mechanic said he would take a look but that I still had to signature the work where potential labor/parts costs could be involved if they found something otherwise. I understand their thinking as they are covering themselves but I mentioned it's pretty hard for it to be "something else" with one hour on the bike. He agreed and said he'd call me if there was a conflict. He rode it and noticed what I did.....even performed a leak test(it passed) he agreed a warranty claim was in order and called headquarters. They nixed it on the grounds that all the 05's come lean to pass 50 state emmissions. What we are seeing is simply a case of lean jetting. So, the mechanic(and headquarters) suggested a jet kit. I agreed since I don't want to detonate a new engine with lean jetting. They will also remove the baffle at the time of jetting. We went JD but alas....the company ran out of kits so we are on back order for a week. When I got home, I re-read the 30 day warranty and near the end it reads "warranty does not cover carburaetor". Swell! In the end, I will have to shell out a couple hundred bucks for the kit and labor. Is this right? I new the bikes came lean with the AIS and all but I didn't figure so lean that the bike wouldn't idle correctly. I guess the jet kit will tell the story but I'm curious if any of you new 05' owners have had a similiar experience? I'm having the dealer jet it because I'm not good at tearing into the newer carbs, they have the tools to do it right and if something's off they will work until it's corrected. Lastly, what would you do if the kit doesn't fix the problem? Any other troubleshooting to consider? Wish me luck!