Ok, maybe not but I did make mine a lot more like my ’03, better actually. I’m amazed with the suspension every time I ride this ’06, but after coming off an ’03 YZ450 I wasn’t totally thrilled with the motor. I spent some time and money on it and I’m very pleased with the results, I ended up with much better throttle response and more power everywhere. Here’s what I did… I bought a Vortex ignition, a can of Ultimate 4 and spent some time getting the jetting better. Now I only have one ride so far with the ignition, (80 miles of tracks, hillclimbs and fast trails) but I think I have a pretty good idea of what it did to the bike. Throttle response in neutral was very different from the stock box to the Vortex, the stock ignition felt a little retarded when you revved it compared to the Vortex, a little slower revving. The difference between the stock map and the “best performance” map isn’t huge, but it is noticeable. I know it's noticeable because I accidentally bumped the handlebar switch once without knowing it. I was riding and was wondering why the power felt a little soft, looked down and saw the switch in the stock map position. The best way I can describe it is the stock ignition didn’t like to pull out of the lower revs without a little jab at the clutch. With the Vortex it pulls up into the power better when it’s down low in the rpms, like coming out of a corner. I think if you could switch between the stock box and the Vortex when you’re actually riding it would be a much more noticeable difference. The difference between the “traction” maps and the “best performance” map is huge, anyone would be able to notice the difference. At first I thought I was going to take the handlebar switch off because why would I ever want to use anything but the best performance map, until I did one of my favorite hillclimbs. This climb is very technical with two jumps, a few turns and lots of trees to hit if you’re not careful. I found that I could get way more speed up it on the ’06 vs. the ’03 because of the smoother power delivery, until today. With the Vortex, jetting and U4, it was like doing the hill on the ’03, very difficult to get a good drive around the first turn up the hill. Too much wheel spin or too hard to keep the front end down. With a flip of the handlebar switch to one of the traction maps, I was able to get a much smoother drive around the first turn and got way more distance off the jumps because of it. The point is, the hard-hitting power is fun, and I’m glad I spent the money to get it, but I will be using the softer hitting maps once in a while. Those guys at Yamaha aren’t stupid, that’s what they learned with the ’03, hard-hitting power doesn’t always mean faster lap times. But it sure is fun! Here’s what I learned on the jetting, I believe the 48 pilot and the 170 main are too rich for this bike, at least with the Vortex ignition and an FMF TiQ. (I don’t have a choice, I live in CA and I have to run a 96 db pipe.) Even running the U4 it still seemed too rich. I went back to a 165 main and the top end over rev was much better. I was hitting the rev limiter in 4th gear, even with it being higher than stock with the Vortex. (550rpm higher than stock.) I put a 45 pilot in it and the off-idle was much cleaner pulling, backfiring was ok, once in a while but not excessive. Between the Vortex ignition’s more aggressive advance (I’m assuming) and leaning out the pilot, the 1/8 to ¼ throttle response is a huge difference from what it was with the 48 pilot and the stock ignition. When ncmountainman mentioned that his fuel mileage was way better when he put a Vortex on his bike, I thought he was smoking something (sorry, it did sound a little unlikely) but I think it’s possible. If you do a lot of riding at 1/8 to ¼ throttle, the pull will be much stronger so if you were easy on the throttle you probably would get a little better mileage. After all, the best fuel mileage is usually when the timing is advanced as far as the motor and fuel will allow. I tend to spend too much time at full throttle, so my bike drinks gas like crazy! I have to add though, there’s not much of a difference in the WOT performance between the stock ignition and the Vortex, the big difference is in the low-end throttle response. There have been plenty of posts about the U4 fuel, I’ve used it before and I know it makes a difference. I’m not sure if I’ll keep using it, $60 a can is a little excessive. It does make HP though, no doubt about it. Sorry about the long post, I hope this helps anyone that has an ’06 and wants a little better low-end throttle response and power out of it. And if you’re running any kind of spark arrestor or 96db pipe, you might want to try putting the 165 main back in it, and possibly even a 45 pilot too. Completely eliminating the decel backfiring means you’re probably giving up some off-idle response. Oh and BTW, I don't get a spiff from Mike at MT Racing if I sell some of his Vortex ignitions! Heck, he wouldn't even give me a discount when I told him ncmountainman sent me. He was probably like "Who the hell is ncmountainman?" Mike seems like a nice guy though and he obviously knows what he's doing with setting up these ignitions.