New For 2004! FMF Factory 4

With the involvement of multiple Factory teams and riders, FMF Racing decided to design and manufacture a premier exhaust system that offers significant performance gains and brings some new and unique features along with it.


The Factory 4 muffler uses FMF¿s unparalleled oval to round construction using military grade titanium and is offered in either a natural or an anodized blue finish. Leading into the muffler is a formed tapered stainless steel inlet. The oval shape combined with the tapered inlet allow the muffler to be routed further forward without interfering with the rear of the bike and subframe. This lowers and centralizes the machines center of gravity which improves handling without sacrificing silencer volume and durability. Its shorter length is less susceptible to damage. The muffler has a modular rear end cap enabling you to change it to suit your desired sound level and powerband. Preceding the muffler is a Powerbomb titanium header and titanium mid pipe which are CNC multi-axis bent and TIG welded for optimum fit and strength. The big-bore 450cc and up motors get the new “Factory Forward” Powerbomb titanium header to further centralize the weight with the optimum tuned length. Also new for 2004 is the modular exhaust port flange which offers a better seal, transmits less vibration and puts less tension on the exhaust system when riding to the extreme.

Unlike any other company, FMF¿s 4-stroke division includes at no charge a Power Up jetting kit for optimum jetting tuneability and their “remove before flight” wash plug with every Factory 4 System sold.

The Factory 4 System is designed to broaden the powerband and give an increased overall horsepower and torque gain while reducing and centralizing the weight.

Motorcycle Applications
Honda CRF250/450 2004
Kawasaki KX250F 2004
KTM 450/525 2004
Suzuki RMZ250 2004
Yamaha YZF250/450 (WR) `03-¿04

ATV Applications
Honda TRX450R 2004
Kawasaki KFX400 `03-¿04
Polaris Predator 500 `03-¿04
Suzuki LTZ400 `03-¿04
Yamaha YFZ450 2004

For more information on the Factory 4 System visit the FMF web site at or contact FMF Racing direct.

FMF Racing
18033 S Santa Fe Ave.
Rancho Dominguez, CA 90221-5514
ph:310.631.4363 fx:310.900.5699