The RS-4 features some of Yoshimura’s most advanced engineering yet. The system utilizes a high flow duplex chamber that acts as a secondary mechanical baffle without interfering with exhaust flow. This means you’ll get great performance without having to deal with the excess noise usually associated with high-performance exhausts.
The RS-4 also features interchangeable volume inserts to tune the exhaust to meet the noise requirements of any track, from the USFS approved insert to the AMA Pro racing legal insert. These inserts add to the RS-4’s flexibility, making it a great investment for any KX250F owner.
RS-4 exhausts are available as a Slip-on, or as part of a full Yoshimura system. The RS-4 Slip-on is constructed from stainless steel and aluminum alloy for lightness and strength, and the full systems are available in stainless/aluminum, full titanium, and titanium/carbon for the professional racer. As with all Yoshimura products, all RS-4 systems are made from the high quality materials that will stand up to even the toughest conditions.