Quick view Slip-on system w/Sport Muffler Yamaha YZF 450 2004-2009 SKU: AT-6403SP Compare $279.99 SPORT Series ATV Exhaust MBRP Sport Series mufflers offer a mild exhaust note over their Utility Series systems, taking full advantage of the reliability and dependability of a chambered design, while increasing flow. Enhanced Exhaust Sound 1.75" Inlet,... Add to Cart Add to Cart Add to Wish List Add to My Wish List Create New Wish List