Yoshimura YZ450F 20-22 RS-12 Stainless Full Exhaust, W/ Aluminum MufflerYoshimura YZ450F 20 22 RS 12 Stainless Full Exhaust, W Aluminum Muffler Yamaha' s YZ450F is one the bikes that seems to win the accolades of media testers of almost every level. We set out to make an even better experience with big blue. It's no secret that the YZ450F has tons of power and torque, so we focused on smoothing the transition of both. Our new RS 12 responded perfectly, maximizing mid top power and torque to boot! With the power transition