Shopping CartCLOSE
Shop 2020 Riding Gear For Dirt Bike And Street Bike >
FMF Factory 4.1 Slip-On Exhaust
FMF Factory 4.1 Slip-On Exhaust

$359.99 - $404.99
10% Off - Save up to $45.00

Item #FMF0003

Read More
12 Reviews
4.4 out of 5 stars
5 Star   8 4 Star   2 3 Star   1 2 Star   1 1 Star   0
All Reviews
Wild thing Verified Purchaser
2 months 5 days ago Marlboro nh
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Easy to install

Makes the bike sound and look awesome

Op57 Verified Purchaser
1 year 4 months ago Slidell La
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Looks great sounds even better

Bought the factory 4.1 with the stainless meg a bomb for my 06 yz250f also did the jd jet kit couldn’t be happier sounds great and runs great

JWOW Verified Purchaser
1 year 5 months ago
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
FMF 4.1

This exhaust sounds better then your mom mid power band. Feels greats and turns heads when flying by.

Hondaguy325 Verified Purchaser
1 year 5 months ago Wisconsin
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Awesome exhaust

Really woke the bike up paired with the mega bomb header quality pipe easy instal and great sound

2 years 11 months ago
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
Awesome product

I love this fmf, adds lots of power and sounds great. Very easy to install which is good.

Over 3 years ago
Durability4/5Ease of Installation4/5Performance5/5Power3/5Style5/5

I got this as a Christmas present, it added plenty of power to my crf 150r and installing it wasn't that hard. If it broke which it hasn't after 2 years, I would defiantly buy it again.

Newt Verified Purchaser
Over 4 years ago
Durability5/5Ease of Installation5/5Performance5/5Power4/5Style4/5

stone Verified Purchaser
Over 4 years ago United States
Durability3/5Ease of Installation1/5Performance3/5Power3/5Style5/5

I like the exhaust and power bomb header a lot! The only problem I had with this was installing it. It was a huge pain in the you know what. You have to buy your own clamps to secure the power bomb header to your exhaust. You also need to buy high temp silicone. This costs about $30, and you also have to let it sit for 24 hours for the best outcome. Other than that it took me about 30 minutes to take the old exhaust off and put the new one on. Hope this helps to future customers.

Colby Verified Purchaser
Over 5 years ago Port Orchard, WA, USA
Durability5/5Ease of Installation5/5Performance5/5Power5/5Style5/5
FMF Factory 4.1 Slip-On Exhaust

Love this pipe! Was easy to install, sounds great, and excellent power increase. (I also installed a power bomb)

Over 8 years ago Elkhart indiana
It goes ham with the mega bomb

I like it it added lots of power I was riding on the road and went to full throttle for a race takeoff and my tires just got to spinning. Very good buy check my bike out on Facebook. scar ray is my name on there

See 2 More Reviews
16 Questions
Answered:   15
Not Yet:   1
Q: Do you have to get a jet kit for this exhaust???
Over 5 months ago
Top 10
Over 5 months ago
A: We do not offer a exhaust specified jet kit.
Q: How much horse power would the slip on add to a 2008 Honda 150r
Over 9 months ago
Dan Gearhead
Top 25
Over 9 months ago
A: FMF doesn't list horsepower specs for your bike as there are many factors that could go into the final horsepower numbers like Dyno used, atmosphere pressures and existing modifications done to your bike.
FMF Factory 4.1 Slip-On Exhaust
Q: Dent on mid pipe 06-09 yz250f
2 years 11 months ago
On the side of the mid pipe on the side that is closest to rear shock there is a dent that is meant to be there to clear the spring or did I receive a bad mid pipe.
Q: Would it fit a 2016/17 crf230f?
2 years 11 months ago
I'm getting a new dirt bike will highly likely get a 2016 crf230f or I might wait for the 2017 model and I want to mod it like crazy whichever bike I get thanks mate
Top 500
2 years 11 months ago
A: The FMF options for the 16/17 CRF230F is the powercore 4 and the Q4 Slip on exhaust!
Q: Can you get a spark arrestor
Over 3 years ago
Expert MotoSport Staff
Over 3 years ago
A: No, sorry.
Q: KTm sxf250 2006
Over 3 years ago
will fmf 4.1 fit on my stock header pipe??
MotoSport Staff Expert
Over 3 years ago
A: For the most part yes. FMF builds their systems to be fully interchangeable between all FMF products and stock components. This way you don't have to worry about something not fitting down the road.
Q: Does this have a mid pipe, that would directly fit to the fmf powerbomb header?
Over 4 years ago
Does this have the mid pipe included
Top 10
Over 4 years ago
A: Yes, the FMF Factory 4.1 Slip-On Exhaust comes complete to mount to the header. feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.
Q: Old newer dual exhaust fit on older models?
Over 4 years ago
I have a 2006 crf250r and I was wondering if like the new dual exhaust slip on pipes made for the 2015 model would fit on my 2006? Or any after market dual exhaust pipes for that madder
MotoSport Staff Expert
Over 4 years ago
A: No, the 2015 CRF250R exhaust will not work on the 2006.
Q: What is the db rating for this exhaust without a spark arrestor or quiet insert?
Over 4 years ago
Top 10
Over 4 years ago
A: FMF does not have a db rating for the Factory 4.1 Slip-On Exhaust without the insert. FMF rates the insert as a 94db unit. .
Q: Would i need to re jet my carb from stock for this pipe and the powerbomb? i bought my bike with this pipe and a little smoke comes out occasionally?
Over 5 years ago
My 2008 yz450f came with this pipe on it and i recently added a powerbomb head pipe made by FMF and have great power gains. although i got my bike used it was in really good condition! but it puts out a little smoke? i was wondering if it is a jetting issue or oil getting past the rings on the piston. i checked my air/fuel screw and it was at 2 turns out from all the way turned in. ive always heard thats stock specs.. it takes a few kicks to crank but it runs strong!! please help ? does it sound more like it needs a new jet? if so which one and what size should i go with? or is it a piston and ring ? what little bit of smoke i see come out of my pipe looks blue and a friend of mine says it looks like it could be black..
Expert MotoSport Staff
Over 5 years ago
A: 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.
1 - 10 of 16

See all bikes that this part fits...

See Fitments
# Part Numbers
Product Variant Manufacturer Part #
Blue Anodized Titanium With Stainless Steel Mid Pipe 044235
Natural Titanium With Stainless Steel Mid Pipe 041171
Natural Titanium With Stainless Steel Mid Pipe 042061
Natural Titanium With Stainless Steel Mid Pipe 042101
Blue Anodized Titanium With Titanium Mid Pipe 041291
Natural Titanium With Stainless Steel Mid Pipe 044211
Natural Titanium With Stainless Steel Mid Pipe 044206
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.

Added to your cart