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FMF Factory Fatty Pipe
FMF Factory Fatty Pipe

$ 215.99 - $ 224.99
10% Off - Save up to $25.00

Item #FMF00E4

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30 Reviews
4.9 out of 5 stars
5 Star   27 4 Star   3 3 Star   0 2 Star   0 1 Star   0
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All Reviews
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Solid performance and looks

So happy with this purchase

Top 500 Verified Purchaser
Lake Tapps, Warshington
Durability 4/5 Ease of Installation 5/5 Performance 4/5 Power 4/5 Style 5/5
It’s Factory

Beautiful pipe. Has to be factory. It is a little more maintenance but the blue colors made when it gets hot are awesome.

Verified Purchaser
Waterville, New York
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Awesome starts!!

Since putting this pipe on my bike my starts have been on point!!! Makes the bike look awesome!!

Verified Purchaser
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Best price and service around

I order from motosport a lot my FMF pipe is great love it and will continue to buy from Motorsport best service anywhere

Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Great Exhaust

I paired this header with an FMF shorty silencer on my 2006 YZ250. The stock system is actually difficult to improve upon, but this setup does just that. The power band comes on sooner and stays on longer. Mid range power is excellent. I’ll be sticking with this system for the life of my bike.

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

Pipe looks awesome and opens up the power band a bit. Sounds good, looks sweet and it was here the next day! Motosport rocks

Verified Purchaser
North Idaho
Durability 3/5 Ease of Installation 5/5 Performance 4/5 Power 3/5 Style 5/5
Depends on what you are looking for.

Install was a breeze.
Looks great,
Makes more low end than stock but takes too much off of the top. I put the stock pipe back on for a desert riding trip. Will put it back on when I’m doing steep hill climb days.

Verified Purchaser
Fort Smith, AR, USA
Durability 5/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
A Must Have

Track performance gains are real. Bolts on just like an OEM pipe. Adds a little bling along the way. If your son is racing 125 class, you need this exhaust pipe.

Verified Purchaser
West Coast, USA
Durability 4/5 Ease of Installation 5/5 Performance 5/5 Power 5/5 Style 5/5
Solid product you can depend on

I have tried every major name brand exhaust system on the market and this will alway be the one I choose from now on. I know that every time I install a new pipe from fmf is will be a direct bolt on application with now issues. The head and mud pipe seal is always correct and rarely ever has any exhaust gasses or oils leak out causing a mess and loss of power. Significant impact will sent the pipe but day to day durability is on point.

Ease of Installation 1/5 Performance 5/5 Power 5/5 Style 5/5

My pipe did not come with the rubber rings or springs

See 10 More Reviews
20 Questions
Answered:   18
Not Yet:   1
Q: What is the difference between the sizes?  Cause you can’t big bore a kx100 with a kit
2 months 14 days ago
Q: Can I use the ktm 85 sx sxs cdi with this pipe
1 year 10 months ago
Can I use the ktm 85 sx sxs cdi with this pipe? The cdi says it's made to run with the stock exahust
Q: Can I put the pro circuit r304 silencer on this pipe on a kx100?
2 years 1 month ago
Expert MotoSport Staff
2 years 1 month ago
A: Fitment between manufactures can not be guaranteed. With that said you shouldn't have an issue.
FMF Factory Fatty Pipe
Q: Pipe fitting into YZ Stock silencer
2 years 10 months ago
I have a 2013 YZ-125 and cant afford the pipe and silencer at the same time and need to do it in stages. If I get the pipe first, will it fit into the stock silencer?
MotoSport Staff Expert
2 years 10 months ago
A: You should have no problems running the stock silencer with this pipe on your 2013 Yamaha YZ125.
Q: Would this fit my dep silencer?
Over 3 years ago
Would I be able to use this expansion chamber with my dep silencer of would it have to all be fmf?
Expert MotoSport Staff
Over 3 years ago
A: Most likely it will work but fitment can not be guaranteed with that combo.
Q: Will the SST,the Factory Fatty, or the Fatty be the one that is easiest to keep clean
Over 3 years ago
MotoSport Staff Expert
Over 3 years ago
A: The nickel-plated finish on the SST and Fatty pipes will be easier to clean and maintain than the bare finish on the factory pipes.
Q: What does it increase and decrease?
Over 3 years ago
I have a 2005 rm250 and im looking for a stronger hit in the powerband and more top end pull would this pipe be the best for me?
MotoSport Staff Expert
Over 3 years ago
A: Fatty pipes are designed to give the engine an all around power increase. We are not drastically altering the power band of the bike. This pipe will appeal to most people that are happy with the stock power band and just looking for more useable power everywhere. You would probably want to go with the SST. Think of the SST as a mix between the Fatty, and the Rev pipe with a little help from the rear SST section. This pipe gives an all around power increase similar to the Fatty, yet gives it even more mid and top like the Rev without sacrificing low end. This pipe offers a new power band that wasn't available in the past, with its new technologies.
Q: Ktm jetting
Over 3 years ago
What jetting setup could I run on a 2015 Ktm 250 sx at 1,000 -2500 elevation in 80-90 weather. Thanks
MotoSport Staff Expert
Over 3 years ago
A: There is not a specific setting I could give you for jetting your bike. It would really depend on 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: Why wont it work on a yz 125 2004 i really like this pipe but dont understand why its not working.
Over 3 years ago
if I have a 04 and this pipe that i like wont fit should i order the 05 one or will it not fit?
Expert MotoSport Staff
Over 3 years ago
A: Unfortunately FMF does not offer the FMF Factory Fatty Pipe for your 2004 Yamaha YZ125. In 2005 Yamaha switched from the steel frame to the aluminum frame on the YZ125. Because of that the 2005+ pipe will not mount on the 2004.
Q: Does this pipe come the same shape and style like the photo if bought for. 2015 ktm 125 and will it fit onto a titanium 2 silencer and how more HP
Over 3 years ago
MotoSport Staff Expert
Over 3 years ago
A: The image is a generic image supplied by the manufacturer for reference only. It may not be displaying the exact part for your bike. 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 pipe 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.
1 - 10 of 20

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See Fitments
# Part Numbers
Product Variant Manufacturer Part #
FMF Factory Fatty Pipe N/A
Big Bore 022058
FMF Factory Fatty Pipe 022064
Standard 025222
Big Bore 025224
FMF Factory Fatty Pipe 021051
FMF Factory Fatty Pipe 021043
FMF Factory Fatty Pipe 021055
FMF Factory Fatty Pipe 025076
FMF Factory Fatty Pipe 025121
FMF Factory Fatty Pipe 025072
FMF Factory Fatty Pipe 025133
FMF Factory Fatty Pipe 025101
FMF Factory Fatty Pipe 025103
Standard 025090
FMF Factory Fatty Pipe 022062
FMF Factory Fatty Pipe 023058
FMF Factory Fatty Pipe 023043
FMF Factory Fatty Pipe 024052
FMF Factory Fatty Pipe 024056
FMF Factory Fatty Pipe 024039
FMF Factory Fatty Pipe 022032
FMF Factory Fatty Pipe 022055
FMF Factory Fatty Pipe 025183
FMF Factory Fatty Pipe 025198
FMF Factory Fatty Pipe 025161
For Supermini 025154
FMF Factory Fatty Pipe 25157
Big Bore 22063
FMF Factory Fatty Pipe 25204
FMF Factory Fatty Pipe 23065
California Proposition 65

WARNING: This product contains chemicals known to the State of California to cause cancer, and birth defects or other reproductive harm. Wash hands after handling. For more information, go to www.P65Warnings.ca.gov.