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FMF Q4 Slip-On Exhaust

(3 reviews)

Item: 327238

$323.99 – $404.99

Select Your Vehicle - Fitment Guaranteed

FMF Q4 Slip-On Exhaust

FMF has always been a leader in high performance exhausts that won't wake up the neighborhood thanks to their inherent quiet technology. The Q4 muffler is no exception in the off road exhaust market. FMF has applied for several patents making it one of their most technically advanced products. The Q4 employs an intricate array of chambers, baffles and proprietary multistage packing material making it one of the best- performing quiet mufflers available. It's quiet technology in quite a svelte muffler package!

  • Developed over years of championship off-road racing
  • Max sound output 96dB
  • Significantly lighter than stock
  • Constructed using an aircraft grade aluminum sleeve and high strength stainless steel components
  • Fitted with USFS-approved spark arrestor
  • Easily serviced for repacking
  • Made in the USA
Specification Details
Color Varies (make selection above)
Configuration Varies (make selection above)
Country of Origin USA
Mid-Pipe Varies (make selection above)
Muffler End Cap Varies (make selection above)
Muffler Sleeve Aluminum
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.

  • CRF150F 2003-2017
  • CRF150R 2007-2009, 2013-2021
  • CRF230F 2003-2009, 2012-2017
  • CRF250R 4-Stroke 2004-2005
  • CRF250X 4-Stroke 2004-2009, 2012-2017
  • XR650L 1993-2009, 2012-2021
  • KL650B Tengai 1990-1991
  • KLR600 1984-1986
  • KLR650 1987-2018
  • KLX300R 2020-2025
  • KLX400SR 2003-2004
  • DR-Z400E 2006-2007
  • DR-Z400S 2000-2024
  • DR-Z400SM 2005-2009, 2012-2021, 2023-2024
  • DR650SE 1997-2014
  • WR250F 2003-2013
  • WR450F 2003-2011
  • YFZ450 ATV 2004-2009, 2012-2013
  • YFZ450R ATV 2009-2023
  • YFZ450X ATV 2010-2011
  • YZ250F 4-Stroke 2003-2013
  • YZ450F 2003-2009

Customer Reviews

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Good buy!

By   on 

Fit perfectly and paired it with the power bomb header. It's much more neighbor friendly in the areas I ride than the 4.0 slip-on it replaced. Maybe some loss of power but can't say for sure since I swapped out tires as well.

All the performance without all the noise

By   on  Verified Purchaser

Perfect pipe for my Honda XR650L. It weighs significantly less than stock, is trail and track legal and looks and sounds amazing. Great sound and performance without being obnoxious. Perfect when trying to stay under the radar of law enforcement and park rangers.


By   on 

Great pipe! Sounds awesome and is USFS approved for trail rides.

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Questions & Answers

Ask Question

Does this have a spark arrester

Yes, the Q4 does come with a USFS spark arrestor installed.

By Andy
Answer Question

Does this fit a 2005 Yamaha rapter 660?

Yes, so long as you choose that 2005 Yamaha Raptor 660, you would receive the correct FMF Q4 to fit it.

By Andy
Answer Question

will this fit a 2019 suzuki drz400s? and is there a guard so I can protect my wolfman saddle bags?

Yes, if you were to select the 2019 Suzuki DR-Z400S FMF Q4 muffler from our fit guide, you'd receive the correct muffler to fit your exact bike. As to your second question, unfortunately no, none of our suppliers carry a guard that'll bolt straight onto that machine. You may want to consider add an Acerbis Muffler protector to your order as that'll provide some additional insulation over the muffler sleeve. You can easily wrap that round the muffler wherever you think it's most likely to come into contact with your saddlebag.

By Staff
Answer Question

Will this fit a 2007 xr650l

Yes, if you were to choose the 2007 Honda XR650L slip-on muffler from our fit guide, you'd receive the correct exhaust to fit your machine.

By Staff
Answer Question

Does it come with all mounting hardware?

In most cases, FMF exhausts require that you re-use some of the OEM exhaust mounting hardware in order to complete the installation of the muffler. These are parts such as the bolts used for hanging the muffler from the subframe and the clamp between the header and the muffler. Otherwise, any bespoke items, like the bracket that goes around the muffler, are included in the box. So long as you have the stock exhaust on your machine, you should have no problem fitting this, or any other FMF exhaust we sell.

By Staff
Answer Question

stock exhaust

I got a 2001 raptor 660r and I was wondering if the original exhaust pipe work with putting this on? I'm trying not to spend much money with different exhaust parts!

Yes, the stock Raptor 660 header will indeed fit this muffler. All of FMF's Q4 slip-on mufflers are designed to work with the stock exhaust pipe. Plus, should you decide later on that you want to get an FMF header, the muffler is compatible with all FMF headers that will fit your machine.

By Staff
Answer Question

Will this fit Suzuki DRZ400E 2007? I only see "S" and "SM" models listed. AFAIK the header pipe on "E" is different size.

No, this muffler will not fit any DR-Z400E model. The reason is, as you've noted - the header diameters between the S/SM models and the E variant are different. Consequently, this muffler will not fit that bike. We do, however, have a 2007 DR-Z400E Leo Vince X3 Enduro Slip-On Exhaust that will fit that bike. It'll bolt straight onto the OEM header without issue!

By Staff
Answer Question

Will this fit a 2013 CRF150R?

Yes, we do have an FMF Q4 slip-on exhaust to fit the Honda CRF150R. Just choose your exact machine from our fit guide that's immediately to the right of the main image on our webpage and you'll be sent the right exhaust for your bike.

By Staff
Answer Question

Would this fit an ssr125 header?

If not what US Forestry Dept Approved fmf pipe would?

FMF Q4 mufflers are designed only to fit motorcycles and ATVs equipped with a stock or an FMF header. In that light, if the OEM muffler fits the SSR header that you have, then there's a good chance the FMF Q4 will also fit. Otherwise, if the SSR header came as a kit with its own muffler, or is designated only to fit SSR mufflers, then this, or any other muffler we sell, is not going to fit your needs - you'd have to source the correct muffler from SSR.

By Staff
Answer Question

My 2006 CFR 250R has dual exhaust and very loud. Will the FMF Q4 slip directly into the header and fit? I would pull the dual exhaust and the pipes that split coming out of header.

Provided the header you're referring to is the OEM Honda header, then yes - the FMF Q4 will slip directly onto the header. It would replace the split coming from the OEM header and you'd go from a dual-muffler configuration to a single muffler exhaust.

By Staff
Answer Question

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