FMF Carbon Factory 4.1 Yamaha YZF 06-09/WRF 07-10 homologated muffler

FMF FACTORY 4.1 CARBON SYSTEM YAMAHA YZF, WRF, KAWASAKI KXF (2006-2010) - FOR YZ 250 F, YZ 450 F (2006-2009) - FOR WR 250 F, WR 450 F (2007-2010) - FOR KX 250 F, KX 450 F (2009) The Factory 4.1 incorporates the latest in FMF Resonance Chamber Technology both internally and externally. In addition, we achieve a shorter overall length that is less susceptible to crash damage and complementary to our Factory Forward Engineering - moving the muffler closer to the motor to centralize mass. The Factory 4.1 is constructed from only aerospace grade materials that meet our exacting specifications and is manufactured 100% at our Southern California factory. Features: Massive Power gains throughout the RPM range. Huge weight savings. New RTS (Rapid Tuning System). Can be used with FMF or Stock OEM Header. For Yamaha YZ 250 F, YZ 450 F (2006-2009), WR 250 F, WR 450 F (2006-2010) and Kawasaki KX 250 F, KX 450 F (2009).