With the 250 class being the first step in motocross glory why would you even consider keeping your bike stock. A scratch of paper, some experienced fabricators and a dyno is where an exhaust system's design starts and what comes out is a system like Yoshimura's KTM 250 SX-F RS-4 Exhaust System. This exhaust system incorporates Yoshimura's RS-4 Polyresonant Duplex Chamber technology along with their two-staged stepped baffle giving your KTM 350 SX-F enough breath to rocket you to the front of the pack. All you need now is tons of natural talent. There's options depending on how deep your pockets go but the end result is a exhaust system that was engineered from the ground up to be the best of the best. This all adds up to a system that can't be denied when you're on the hunt for a new set of lungs for your KTM 250 SX-F.