Just bolted the new DSP supercross exhaust kit and henry air box w/ the velocitcy stack on a cpl of days ago. Man what a difference!!! This totaly changes the bike. It pulls like a hopped up 250 two smoke. 3rd gear trough the woods is no problem. You dont need to bang gears like a 125 any more. The bike rips off of dead idle!!! no bog or pop. The bike breaths fire. I weigh 193 and this bike pulls very hard and smooth. You skinny guy will think your on a 426 with this set up. Its expensive though. $952 for the torque simular to the 426. You will have to change jetting.No big deal its very easy.