Based on the successful exhaust pipe used by pro riders 19-gauge steel used on the header portion for optimum strength and durability; 20-gauge steel on body and rear section for increased weight savings Seams are hand pounded after stamping process...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

The Factory 4.1 RCT incorporates FMF Resonance Chamber Technology™ both internally and externally Shorter overall length that is less susceptible to crash damage and complementary to FMF's Factory Forward Engineering - moving the muffler closer to the motor to centralize...

FMF FACTORY FATTY EXPANSION CHAMBERExtra strong sheet steelUntreated surfaceHigher maximum powerHigher speedFull soundBetter power deliveryUncompromising race lookCombination with FMF silencer recommended Product Info:  Our stock photos shown are of the actual item. Brand new directly from FMF in original packaging....

The Factory 4.1 RCT incorporates FMF Resonance Chamber Technology™ both internally and externally Shorter overall length that is less susceptible to crash damage and complementary to FMF's Factory Forward Engineering - moving the muffler closer to the motor to centralize...

Built to provide excellent power for today’s tracks geared toward 4-stroke machines Smooth power curve throughout the RPM range Large diameter canister for more tenability and longer lasting packing life Delivers a crisp, notable sound Optimally designed to complement performance...

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...

The Factory 4.1 RCT incorporates FMF Resonance Chamber Technology™ both internally and externally Shorter overall length that is less susceptible to crash damage and complementary to FMF's Factory Forward Engineering - moving the muffler closer to the motor to centralize...

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...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

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...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

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...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

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...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

RCT (Resonance Chamber Technology) features a patented core shape that lowers decibels while maintaining maximum power output Internal ducts in the chambers of the RCT system increase internal volume for improved exhaust flow, resulting in power gains throughout the entire...

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...

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...

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...

The Factory Fatty is reminiscent of the “works” or cone pipe once used by Factory Teams and it shares many of the same characteristics with its craftsmanship and material quality Broadens and smooths out the power curve while boosting gains...

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...

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...