I recently cut out the side panel of my '03 650R and did the whole screen & rivets. The bike has the HRC intake, spark arrestor, and needle jet. I also run a Twin Air Power-Flow kit. The stock carb was jetted with a 68S pilot (2 1/4 - 2 1/2 turns out on the mixture screw), and a 170 Main jet, which way a tad rich, but the bike seemed to like that as far as power. Now, with the cut out side panel, I had to turn the pilot screw out to 3 - 3 1/4 turns out. The main jet seems okay as it has much more power on the top without and hesitation. Do you think I would benefit from a 70 pilot jet instead of the 68S? Is there a 70S pilot jet? If so, does anyone have the part number? Also, even with the pilot jet adjusted as well as it can be right now, I have quite a backfire POP problem. Is the "plug the hole" in the air cut-off in the carb a good thing to do? I saw that on http://www.xr650r.borynack.com/xr650r_caruretor.htm.