The Factory 4.1 RCT incorporates FMF's Resonance Chamber Technology™ both internally and externally
In addition, FMF achieves a shorter overall length that is less susceptible to crash damage and complementary to their Factory Forward Engineering - moving the muffler closer to the motor to centralize mass
The Factory 4.1 RCT is constructed from only aerospace grade materials that meet their exacting specifications and is manufactured 100% at their Southern California factory
Massive Power gains throughout the RPM range.
Huge weight savings
RTS (Rapid Tuning System)
FITS 2016-2018 Yamaha YZ 450 FX, 2016-2018 Yamaha WR 450 F, 2014-2017 Yamaha YZ 450 F