The dealer I purchased my '07 450 from said they switched out the too-lean stock jetting for a better set up before I picked the bike up and took it home. I never bothered to check what they did, since they deal with these bikes a lot I figured they probably had a pretty good idea of what makes them run good. And I'm pretty sure mine does run good. I'm not real familiar to how these 450's usually behave, but mine seems to run great and pulls hard. Tonight I checked what main they put in the bike, its a 178. I didn't check the pilot because I don't have a screw driver short enough to do so, and I didn't feel like pulling the carb off to look (I was bored, but not that bored). So I check the jetting thread at the top of the page, lo and behold I don't see where anybody is running anything close to that size. Mostly 165/168, somewhere in there. We are right on the dunes, so I figure maybe they really richen them up so some yay-hoo doesn't melt one down on the sand on the first ride. The bike did come with some different jets, so I might play around with it sometime. Right now it runs good so I might not mess with it. Just thought it was weird.