FMF's Factory 4.1 RCT SL slip-on muffler incorporates the latest in RCT (Resonance Chamber Technology) both internally and externally. The core's shape lowers decibels without compromising power output. In addition, FMF designed the muffler specifically to achieve a shorter overall length so as to be less susceptible to crash damage. Complementary to FMF's Factory Forward Engineering, the muffler is also moved closer to the motor to centralize mass and improve handling. Each FMF Factory 4.1 RCT slip-on muffler is constructed from only aerospace grade materials that meet the California company's exacting specifications.
Massive power gains throughout the RPM range
Huge weight savings when compared to the stock muffler
Fabricated using the highest quality proprietary blend of alloy grade materials
FMF RTS (Rapid Tuning System) makes for easy exhaust insert changes
Includes USFS-approved spark arrestor and 94 dB sound insert
Fits OEM or FMF headers
Comes with all required mounting hardware and easy-to-follow installation instructions
Made in the USA
Product Note:
Specification
Details
Color
Varies (make selection above)
Configuration
Varies (make selection above)
Country of Origin
USA
Finish
Varies (make selection above)
Mid-Pipe
Varies (make selection above)
Muffler End Cap
Varies (make selection above)
Muffler Sleeve
Varies (make selection above)
USFS Approved Spark Arrestor
Yes
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.
Best purchase yet for my dirt bike it looks killer with it on there. Somehow it was shipped to me in 1 day can't ask for no more, good quality parts and good customer service.
Fmf 4.1
By Donnie on
Verified Purchaser
Highly recommend, good prices, good quality and fast shipping. Love this exhaust, best purchase yet.
FMF & Happy!
By Bryan G. on
Verified Purchaser
My FMF showed up on time and was not missing anything I needed. Sound is great and increased performance.
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Yes, we do indeed have the FMF Factory 4.1 RCT SL exhaust for the Husqvarna FC 250. Just choose your exact machine from our fit guide and you'll be all set!
Yes, if you were to select the 2013 KTM 450 XC-F FMF Factory 4.1 RCT SL Slip-On Exhaust from our fit guide, you'd receive the correct muffler to fit your bike.
The year seems to be missing from the drop down menu. Does this fit the 2015 YZ250F?
FMF certainly does make a muffler to fit your Yamaha.
If you were to select the 2015 Yamaha YZ250F 4-Stroke FMF Factory 4.1 slip-on muffler from our fit guide, you'd receive the correct exhaust for your machine.
Yes, if you were to choose the 2015 Yamaha WR250F FMF Factory 4.1 RCT SL Slip-On from our fit guide, you'd receive the correct WR250F exhaust to fit your machine!
Yes, if you were to choose the 2016 Kawasaki KX250F exhaust from the fit guide that's immediately to the right of the main image, you'd receive the correct muffler to fit your machine.
Just be certain to select the appropriate model at checkout "2015 KTM 500 EXC" and you would have no issue installing this muffler to the 2015 KTM 500 EXC.
Unfortunately, FMF doesn't produce a Factory 4.1 RCT SL slip-on muffler to fit the 2015 Yamaha WR450F. Currently, FMF makes two different exhausts to fit your machine:
FMF Q4 Hex Slip-On Exhaust for the 2015 Yamaha WR450F
and
2015 Yamaha WR450F FMF PowerCore 4 Hex Slip-On Exhaust
Once you select your machine from our fit guide, you'll be presented with the muffler sleeve option. For many bikes, you can choose from an FMF aluminum sleeve with FMF carbon fiber tip, titanium sleeve with FMF carbon fiber tip or titanium sleeve with titanium tip. The options that you see will determine what kind of mufflers sleeve you would receive. Mind you, not all machines have all the options, so for some bikes, you may only be able to select one type of muffler sleeve.
Yes, if you were to choose the 2018 KTM 500 EXC-F FMF muffler from our fit guide, you'd get the correct FMF muffler to fit the big-bore KTM motorcycle!
If you were to choose the 2018 Suzuki RM-Z450 FMF Factory 4.1 RCT exhaust from out fit guide, you'd certainly receive the right FMF pipe to fit your bike!
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.
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!
Verified Purchaser
