The Factory 4.1 is FMF Racing's premier ATV performance exhaust. It is guaranteed to produce more horsepower throughout the entire RPM range. If performance is your priority, the Factory 4.1 is the exhaust for you.

• Titanium construction with durable stainless steel midpipe
• Used by Factory teams such as KTM, Epic Can-Am and Rath Racing
• Optional quiet insert or spark arrestor available
• Available in natural or blue anodized finish (depending on model)
• Use with FMF Powerbomb or Megabomb, or stock header

We developed the PowerCore4 to increase the horsepower and torque throughout the entire power curve producing a noticeable power increase that is useable and compatible with every style of riding. Aluminum construction and stainless steel Hi-Flo endcaps make for the perfect balance of performance and strength.

• Aluminum performance muffler with durable stainless steel components
• Completely redesigned for all late model applications
• Removable spark arrestor included

FMF is the leader in high performance quiet technology and our Q4 is the next evolution in off road exhaust. The Q4 employs intricate chambers, baffles and proprietary multistage packing material making it the best performing quiet muffler available. With the Q4 you don’t need to hear the power, just feel the power!

• Developed over years of championship off-road racing
• Max Sound output 96dB; most models below 93dB
• Constructed from aircraft grade aluminum and high strength stainless steel
• Use with stock or FMF header

The science behind the Megabomb header may be our greatest engineering accomplishment to date. You can pay an engine builder thousands or bolt on a Megabomb for as much as a 3hp boost! Plus, the megabomb actually reduces noise levels by as much as 1.5dB. The megabomb header will have you pulling holeshots and dusting all the boys on the way up Competition Hill. Simply bolt it on and go faster.

• Increases output from stock motor as much as 3hp
• Produces long header torque and short header over-rev
• Made from Premium Ti-Metal American material
• Patent pending design

The redesigned PowerBomb is a four-stroke header that incorporates FMF's patented PowerBomb module at a precise location in the initial stage of the header. By positioning this "Bomb" at a key point in the system, increased performance and flow is achieved through the expansion and contraction of exhaust sonics through the system. Result is a flow increase of nearly 10%! The outer chamber in the Powerbomb allows the air to expand, cool and ramp back up at a higher velocity.

Additionally, the PowerBomb is a "pre-muffler" of sorts which helps to lower the bikes sound output by providing more sound absorbing surface area for the sound medium (exhaust gases). On some models, you can choose between a moto or supercross version. The supercross version is designed for more low to mid-range power where the moto version is focused in the mid to upper RPM range.

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Our new Power-Up jet kit makes jetting your carb simple. We've teamed up with Dynojet to produce a kit that offers you a selection of jets and/or needles to get maximum horsepower out of your motorcycle or ATV fitted with an FMF exhaust. The easy to use instructions have diagrams and step-by-step procedures to help you get your jetting where it needs to be, no matter what elevation you ride at. No more driving back and forth to the dealer with a handful of jets and needles with a million questions running around in your head on where to start.

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