FMF Factory 4.1 RCT SL Slip-On Exhaust

Item Number: 327248


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Product Description

FMF Racing

FMF Factory 4.1 RCT SL Slip-On Exhaust

  • The Factory 4.1RCT (Resonance Chamber Technology) muffler incorporates the latest in resonance chamber technology
  • Patented core shape lowers sound levels while maintaining maximum power output
  • Five sided canister shape increases internal volume allowing for the use of more sound absorbing material
  • The new chamber design of the muffler also allowed FMF to enhance and refine exhaust pressure through a series of internal chambers while meeting FIM 2M-Max sound test as well as the AMA 94dB standards

Product Note: For closed course competition use only, not intended for street use.

Spec Details
Configuration Single
Country of Origin USA
Mid-Pipe Varies (make selection above)
Muffler End Cap Varies (make selection above)
Muffler Sleeve Varies (make selection above)
Spark Arrestor Screen Insert (included)

Vehicle Fitment

Fitment is guaranteed or your money back plus free return shipping. Don't waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.


  • CRF250R 2011-2013
  • CRF450R 2011-2012


  • TC 449 2011-2013


  • 350 EXC-F 2012-2014
  • 500 EXC 2012-2016


  • KX250F 2009-2014
  • KX450F 2009-2015


  • RM-Z250 2010-2012
  • RM-Z450 2011-2014


  • YZ250F 4-Stroke 2010-2013
  • YZ450F 2010-2013

Customer Reviews

Questions & Answers

  • Will this pipe fit a 2011 kx450f

    By: Max

    Yes, FMF does make a Factory 4.1 RCT SL slip-on muffler to fit the 2011 Kawasaki KX450F. Simply choose your make, year and model from the dropdown fit guide that's to the right of the main image on our website and we'll get the correct FMF exhaust on its way to your quickly!

    By: Staff

  • Will this fit a wr250r?

    By: Lifeaintnojoke

    Unfortunately, FMF doesn't produce a Factory 4.1 RCT to fit any WR250R models. The only mufflers we have on hand to fit that machine from FMF come in the form of the WR250R Q4 Slip-On Exhaust or the PowerCore 4 Slip-On Exhaust for the Yamaha WR250R.

    By: Staff