FMF Q4 Hex Spark Arrestor Slip-On Exhaust

FMF Q4 Hex Spark Arrestor Slip-On Exhaust
FMF Q4 Hex Spark Arrestor Slip-On Exhaust

$341.99 - $350.99
10% Off - Save up to $39.00

Description See Also: 9 Reviews 7 Questions Fitment
Item #FMF002Z

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9 Reviews
4.9 out of 5 stars
5 Star   9 4 Star   1 3 Star   0 2 Star   0 1 Star   0
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All Reviews
Novicerider
Michigan
Ease of Installation 4/5 Performance 4/5 Power 4/5 Style 3/5
Pretty good

I have 2 small annoyances with this product
1. The muffler sticks out much farther than stock and contacts my plastics. Nothing has melted yet though
2. My stock clamp is too large for this pipe. I didn't buy my bike new so it is possible that it wasn't a stock clamp but I doubt it.
Other than that, it's a nice piece, looks well made, quieter than stock.

Raptor700ratvboys Verified Purchaser
Raleigh, nc
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Perfect purchase

Motorsport are the best

FMF Q4 Hex Spark Arrestor Slip-On Exhaust
Henry
Salt Lake City, UT, USA
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
FMF is the best!!

I installed this on a 2012 WR450F and absolutely love it. I have been using it for over a year and have had no issues at all. It was supper easy to install, I recommend getting the pipe or mega bomb to pair with this, really gives it a nice throaty sound. FMF is, in my opinion, the best exhaust company in the game, and of course this one is no exception, giving my bike more power and fast response. Personally I will have this exhaust system on every bike I own.

kikora
Lisbon, Portugal
Durability 4/5 Ease of Installation 4/5 Performance 5/5 Power 5/5 Style 5/5
Great Exhaust

Bought one few months ago and i couldn't be happier. Sounds great, looks nice, and definitely with more power the bike. Recommended!

FMF Q4 Hex Spark Arrestor Slip-On Exhaust
chestnut250 Verified Purchaser
Phelan, CA
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
FMF Q4 installed on my 2012 CRF450R

Wanting to trail ride my CRF450R requires that I have a spark arrested pipe, which is what drove my purchase for an aftermarket exhaust. After some research I decided to go with the FMF Q4 slip-on. Reason being that it has both a spark arrestor as well as it is <96dB. Racing in AMA D37 we have to pass sound test, which this pipe accomplishes.

Overall Rating: 5 stars. I am very happy with this pipe.

Ease of Installation: 5 stars. Tools required were an 8mm, 10mm, 12mm sockets, ratchet, ratchet extension, torque wrench, and silicone sealant. You could get away without a torque wrench or silicone sealant but I always work by the book.

Style: 5 stars. This pipe fits perfect. The location of the muffler is perfect under the fender. All gaps are even and the muffler to header fitment is absolutely flush and perfect. At first I thought the pipe was damaged when I received it due to a strange crease about 5 inches back from the header, almost exactly 180° from the mid pipe bolt mount but after calling FMF to confirm before starting the installation I was informed this crease is "the factory bend to clearance the frame" and once installed I could see its purpose. When you unbox this pipe dont let this crease scare you like it did me!

Performance and Power: Both 5 stars. The pipe sounds great. Not stupid loud but still with that sweet 450 bark I like to hear. Powerwise, it is just a muffler, there may be a slight increase but it isn't life changing. I don't care what pipe you run, none will give you unbelievable HP gains but the real benefit is the reduced weight. This muffler is quite a bit lighter.

Overall, if you are looking for a muffler with a spark arrestor, a sweet exhaust note, quality construction, made in the USA, and outstanding fitment I HIGHLY recommend this one.

Sorry for the dirty fender
From the side
Mantis Verified Purchaser
New Orleans
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 4/5
Q4 on CRF250L

Really sounds great. Not too loud cruising around town. Pretty loud when your getting on it hard. I don't see it being a problem with the police. I would buy again!

MikeH Verified Purchaser
Durability 4/5 Ease of Installation 4/5 Performance 5/5 Power 5/5 Style 5/5
2014 YZF 250 Install-need larger ID clamp

Performs as described.

Note: factory clamp to header will need to be replaced (too small). Acceptable replacement clamp: Moose Racing 1861-0683 1.94-2.12 inch ID.

It would be nice if the clamp was included with the kit.

Topper Verified Purchaser
Paradise, CA, USA
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Excellent

excellent to ran on your bike. I have a kx 450f it worked good

Troy Top 1000 Contributor Verified Purchaser
Michigan, USA
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Awesome Pipe

I bought this for my 2013 KX450F. It was so easy to put on!! I was looking to lower the DB's down a bit, it did the job. I was also looking for a pipe to ride with on state land so it needed to have a spark arrestor. This pipe was well worth the money. Took 5 min to install.

7 Questions
Answered:   7
Not Yet:   0
maxcrf250l
Q: Is the Q4 Street legal in the EU (Germany)?
Over 8 months ago
Or maybe a hint where/how to best check? Thanks
MotoSportExpert
Expert MotoSport Staff
Over 7 months ago
A: All products sold on MotoSport.com are for US models only. We unfortunately do not have product fitment for non-us models. Also any street legal products are designed for US emissions and laws.
Johnathon168
Location: Florida, USA
Q: I currently have the fmf PowerBomb header on my kx450f and it runs great with no adjustments. Would I have to change or do anything if Added this?
1 year 7 months ago
MotoSportExpert
MotoSport Staff Expert
1 year 7 months ago
A: Normally when installing a slip-on only minor jetting changes are needed, if any at all. If your bike is currently jetted properly you will likely not have to make any changes after installing this slip-on. I would recommend installing the exhaust and riding the bike to see how it is running then tuning your carburetor from there if necessary.
DirtBikeTimmy
Q: What to go with??
2 years ago
I'm looking for a slip-on but every single exhaust talks about great power gains but there is such a price difference between them all. What are the performance differences between the Q4 and the 4.1 RCT?? In your opinion whats the best bang for your buck overall (rating all slip-ons).
MotoSportExpert
Top 1 Contributor
2 years ago
A: The internal combustion engine is very simply put a basic air pump. The more air/fuel you and intake and exhaust from the motor, the more power you will make. HP gains are very subjective to gauge on any one or combination of performance parts. Things like the age of the motor, the tune of the air fuel ratio, the altitude, etc will all have an effect on PEAK HP numbers. Many performance products will not increase your PEAK HP, but rather move the HP to a different RPM range than the stock motor.

The FMF Q4 is designed for quiet forest approved riding. The 4.1 series is the newest and will give you more power than the Q4.
Hansen
Location: Denmark
Q: Does the 2014 ktm 350sxf and the 2014 husky fc350 "share" exhaust??
2 years 2 months ago
MotoSportExpert
Top 1 Contributor Top 50 Contributor
2 years 1 month ago
A: FMF Racing list the same part number on their FMF Q4 Hex spark arrestor exhaust for both the 2014 KTM 350sxf and Husky FE350 motorcycles.
Gregrock68
Q: Compared to the stock exhaust on my 2014 kx250f, how much quieter is this unit? Using this slip on, would the bike require remapping for the effort?
2 years 4 months ago
MotoSportGrantK
MotoSport Staff Expert Top 1 Contributor
2 years 4 months ago
A: Your 2014 Kawasaki KX250F's stock exhaust is around 97 decibels. The FMF Q4 Hex Spark Arrestor is going to be around 94 decibels so it will be a little quieter than stock. Normally when installing a slip-on only minor fuel management changes are needed, if any at all. If your bike is currently running properly you will likely not have to make any changes after installing this slip-on. I would recommend installing the exhaust and riding the bike to see how it is running, then tune your fuel management system from there if necessary.
chestnut250
1 year 7 months ago Location: Phelan, CA
A: It will be a bit quieter, possibly a few dB, which is a difference. Kawasaki changed the 250f exhaust from 2014 to 2015 to meet the AMA amateur mandate of 94dB. Your model ('14) is the louder of the two.

If you are going with just the slip-on no remapping will be required. If you pair it with the mega bomb or a header along those lines it will still run good but remapping would certainly help.
Hondarider
Q: Would this increase performance while keeping it close to stock db's?
2 years 8 months ago
MotoSportRyanT
Expert MotoSport Staff
2 years 8 months ago Location: Portland, OR, USA
A: Yes, the FMF Q4 Hex would be great for increasing performance while still keeping to DB level down.
steve
Q: Is the spark arrestor removable on the FMF Q4 slip-on?
2 years 11 months ago
MotoSportRyanT
MotoSport Staff Expert
2 years 11 months ago
A: Yes the spark arrestor on this Slip-On is removable.

It is an insert held in by one screw in the end cap.
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