Routy wrote on 05/25/11 at 06:03:48:

We have the same elevation. I have an '06. All jets stock, but I reduced the spacer for the same reason you did. My muffler is stock with the baffle out. Actually that didn't make a real difference in performance without the baffle, except higher rpm seemed to breathe a bit better. There's still two plates deep inside the muffler that IMHO are actually taking care of the require back pressure, and the baffle behind it was just for noise reduction mainly. But I did need to turn the mixture screw out about 2 1/4 turns to make the low throttle and idle running decent. Then I de-snorkled the air box and took the lid off and got a new stock air filter. That made it run too lean at WOT with the stock 145 main, so I put in a 150 main. Before the exhaust turned really light gray to whitish, meaning it was too lean. The spark plug looked about the same. With the 150 main it's more like a nice tan color, both the plug and the exhaust. The pilot circuit runs fine on the 52.5 stock jet. I tried a 55 pilot jet, but then i got black smoke and it ran like the choke was pulled half way all the time. So I put in a 52.5 pilot jet with bleed holes, and that helped with having a little smoother throttle response between 0-1/4 throttle. With the stock 52.5 it was more like an on/off switch in slow corners. That made it a little scary when sand or small gravel was on the road.