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FMF Factory 4.1 Complete Exhaust With Stainless Hi-Flo Header
FMF Factory 4.1 Complete Exhaust With Stainless Hi-Flo Header

$269.99 - $287.99
10% Off - Save up to $32.00

Item #FMF000H

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10 Reviews
4.7 out of 5 stars
5 Star   7 4 Star   3 3 Star   0 2 Star   0 1 Star   0
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All Reviews
Verified Purchaser
San jose,ca
Great sound

I've had this exhaust system for over a month now and it sounds great. I have it installed on a klx140l Very deep throaty sound. Fitment wasnt 100% but with alittle tweeking, it fits fine now.

Riverside, CA, USA

way better than the powercore 4
put this on my first dirt bike 2004 ttr125l


This thing is amazing!! It makes my pit bike sound like a 450! Sounds incredibly good! If you want an exhaust for your pit bike.. This is the one!!

Verified Purchaser
kannapolis nc

really easy to install! My kid was smiling ear to ear when he heard his new bike.

Verified Purchaser
Medina, Ohio

I love this exhaust system!

San Jose, CA

Great price, fast shipping, super easy install just don't forget spark arrestor if in cali.

Hot Springs, AR
Great Sound and Great Power

Put this on my yz250f and was expecting only the best when spending 600 on an exhaust. Let me tell you. Best investment I could have made. Gives the bike a completely different sound and you can feel the power it adds on. You get what you pay for. Couldn't be more happy.

Top 250 Contributor
Pittsburgh, PA
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Best Exhaust Ever

I have this set up on my 06 yz250f and it is absolutly amazing. The power gain from it is definitely noticeable over the stock exhaust. Fmf is the only way to go for the best performance exhausts out on the market. This exhaust system also gives the bike a different look. This is a great buy for your bike if your looking to add some more power to your bike.

Durability 5/5 Ease of Installation 5/5 Performance 4/5 Power 4/5 Style 5/5
Fast shipping

bought for a2008 crf 450 stronger mid-range revs a little longer on top .fit with no problems did not have to rejet

14 Questions
Answered:   14
Not Yet:   0
Q: Is there any difference between the FMF powercore 4 and the FMF factory 4.1? Because i have the FMF powercore 4 on my 2014 klx110l and I want to know if the factory 4.1 flows better than powercore 4.
24 days ago
Top 10
24 days ago
A: Jeff,
Yes the 4.1 is a higher flow and considered a racing exhaust.
Q: Do you have this exhaust in stock at this time?
Over 7 months ago
Top 10 Contributor
Over 7 months ago
A: We are currently out of stock for klx 110's.
Q: Will it fit
Over 9 months ago
So this will not fit a lifan 125cc motor? I have the xr 50 frame. I want a fmf for my lifan
Top 10 Contributor
Over 9 months ago
A: I do not carry any exhaust for liflan bikes. We only carry them for the Japanese manufactures.
Q: Recommended jetting
1 year 3 months ago
I would like to purchase this for my son's new 2017 klx110 and would like to know own what is the recommended jetting after installing this pipe so you don't get that bogging and the backfire issue
Verified Purchaser Top 250
1 year 3 months ago
A: This is from FMF web page.

Jetting Results
Main Jet
Pilot Jet
Needle Position
Power Jet
Air Screw
Fuel Screw
Q: Do you have any exhaust for a 2004 ttr 125?
2 years 1 month ago
MotoSport Staff Expert
2 years 1 month ago
A: Yes. Just be sure to correctly select the Year/Make/Model of your bike before ordering so we can be sure to send you the correct exhaust for your bike. Also, feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.
Q: Which exhaust would you recommend for a 2008 ttr 125l? The powercore4 or the factory 4.1
Over 3 years ago
Expert MotoSport Staff
Over 3 years ago
A: Both are great pipes and you most likely will not be able to tell much of a difference in performance between the two on the 2008 TTR125L. The Powercore4 does come with the Integrated spark arrestor where as the on factory 4.1 the spark arrestor is sold separately.
Q: What should i rejet my 2015 klx110l to of i get the FMF Factory 4.1 exhaust?
Over 3 years ago
I have a 2015 klx110l and it is all stock and I'm looking to get the FMF Factory 4.1 exhaust. I was wondering if the jets come with the bike or if i have to get them separately and if i do get them separately then what do i get?
MotoSport Staff
Over 3 years ago
A: Jets are sold separately. There is not a specific setting I could give you for jetting your bike. It would really depend on your location (altitude/temperature) and how your bike is running with the current jetting. Jetting can be very tricky, there isn't one setting that will work everywhere with every bike. I would recommend taking your bike to a local motorcycle dealership’s service department to have your bike properly jetted.
Q: Will this exhaust fit a Lifan 110 cc motor ? Thanks
Over 3 years ago
MotoSport Staff
Over 3 years ago
A: No, unfortunately we don't carry any exhaust systems that will work with Lifan motors.
Rear of exhaust
FMF Factory 4.1 Complete Exhaust With Stainless Hi-Flo Header
Q: Do you stock the quiet core for a 2009 Yamaha TTR125-L FMF 4.1 Factory exhaust I already have?
Over 5 years ago
Looking to quieten the pipe down.
MotoSport Staff
Over 5 years ago
A: FMF does have a quiet core insert available for this exhaust. Although we currently don't have it in stock, it is an item we can get. Please feel free to give us a call if you are interested in seeing about ordering. 1-888-676-8853
Q: Is Motosport honoring the FMF 20% discount?
Over 8 years ago
MotoSport Staff
Over 8 years ago
A: we sure are, it is already included in the prices.
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See Fitments
# Part Numbers
Product Variant Manufacturer Part #
Stainless Steel 041241
Stainless Steel 042110
Stainless Steel 044188
Stainless Steel 044275
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