The carb bore is the same size (36mm). The fuel inlet is different and the slide has a smaller cutaway (2.0 instead of 2.5). This would richen the bike at idle, correct? Other than that the nozzle, main jet, and as far as I know the pilot jet is stock. It is so lean on the pilot circuit that it races while sitting idle. When you ride the bike, it runs great as long as you're in the gas, and the throttle response is great, but when you chop it, it wants to race for a few seconds and act like it's running out of gas. I adjusted the air screw all the way in which made it better, but i'm out of adjustment so I guess this means bigger on the pilot?