Yoshimura KX250/X 21-24 RS-12 Stainless Full Exhaust, W/ Aluminum MufflerYoshimura KX250 X 21 24 RS 12 Stainless Full Exhaust, w Aluminum Muffler In a word, POWER! That's what our new RS 12 Signature Series full systems delivers for the all new Kawasaki KX250 Motocross machine. Our new RS 12 adds lots of power to the new and improved 249cc Kawasaki powerplant. The goal was to add more usable power and torque to almost the entire power curve. Boasting an increase of max HP of 4. 5% (at 12,000 rpm) and a max torque increase