FMF

FMF Factory 4.1 Dual RCT Complete Exhaust W/ Stainless Megabomb

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7 Reviews
6 Questions
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Item #FMF000U

The FMF Factory 4.1 RCT Complete Exhaust With Stainless Megabomb Header - Dual includes the following:

FMF Factory 4.1 RCT Complete Dual Exhaust:

The Factory 4.1 RCT incorporates the latest in FMF Resonance Chamber Technology both internally and externally. It starts at the center with a new core - a patent pending shape enhances and refines the exhaust pressure wave for optimal power output while lowering the sound level. In addition, it achieves a shorter overall length that is less susceptible to crash damage and complementary to the Factory Forward Engineering - moving the muffler(s) closer to the motor to centralize mass. Visible changes to the exterior include a redesigned canister to increase internal capacity for the maximum volume of packing material. The packing itself was not overlooked - a proprietary blend formulated for superior durability and sound attenuation. The final component is a new rear endcap engineered for simple tuning adjustments incorporating a snap ring feature to secure the standard and optional inserts. The Factory 4.1 RCT is constructed from only aerospace-grade materials that meet FMF's exacting specifications and 100% manufactured at their Southern California factory.

Massive Power gains throughout the RPM range.
Quieter than stock.
Huge weight savings.
New RTS (Rapid Tuning System) makes for easy sound insert changes as well as adding U.S. Forestry Approved Spark Arrestor.
#1 Exhaust in 2011 Supercross Series, 2011 Motocross Series, 2011 Motocross of Nations and 2011 Monster Energy Cup!

FMF Stainless Steel MegaBomb Header:

The science behind the MegaBomb header may be FMF's greatest engineering accomplishment to date. You can bolt on a MegaBomb for as much as a 3 horsepower boost, plus the MegaBomb actually reduces noise levels by as much as 1.5dB. Used by Factory Teams, the MegaBomb is the next level technology you can have today.

Produces long header torque and short header over-rev.
Reduces sound output as much as 1.5dB.
Increases output from stock motor as much as 3 HP, alone.

Note: For closed course competition use only. Not intended for street use.

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5 out of 5 stars

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Keyon888 Verified Purchaser

Over 10 months ago Ca

Awesome exhaust for my 2017 Crf450r

This is a great exhaust system, built to perfection and super easy to install! Made the bike sound deeper and the carbon fiber looks sweet! Highly recommend this system

Rhodes406 Verified Purchaser Top 1000

1 year 2 months ago Estill, SC

Great fit n sound

Purchased these as I have had prior FMF exhaust. As expected sounds great along with look sharp. Welds are good and clean. Pleased with them

Jut b Verified Purchaser

1 year 4 months ago Clarklake, Mi

All around worth the money

I purchased this set for my 2017 Crf250 and they sound great! Installation was super quick and easy and has that great throaty low end sound I was looking for. Easily the loudest exhaust I’ve ever personally owned with the spark arrestors out. I will say with the Quiet core spark arrestors in I did lose quite a bit of top end but that was expected. Best purchase I’ve made for my bike by far!

Booner

1 year 6 months ago Cassville, MO 65625, USA

Great sound

2017 crf 450RX. After install I noticed a smoother low end throttle response. Bike didn’t seem as jerky. They also have a great throaty sound. The stock set up was too raspy for me.

jumper

2 years 3 months ago Monroe, MI, USA

Fmf mega bomb header

this exhaust is great i love the sound of it and how much better my bike performs at races i would recound this to everyone that asked how i like this prodest

MXVet916

Over 5 years ago Montana, USA

Love the new sound!

Installed this on my 2013 CRF450R as I wanted to keep the dual exhaust because it looks incredible and sounds even better. Louder than stock without the spark arrestors and that is exactly what I wanted. I removed the air filter screen and then had the local shop remap the ECU . It feels like a big increase in power but some of that may be just the great sounding motor.

Carnage

Over 6 years ago California

Great exhaust system!

This exhaust was the missing link on my 2013 CRF 450R. It made it more snappier and helped the bike pull better instead of flattening out. When I rode with it for the first time I knew immediatley my bike responded better.

Answered: 6

Not Yet: 0

matt a

Q: Is the fmf 4.1 fim and ama approved? what is the diameter of the screen opening? i need to be at or under 0.023. thanks

Over 6 months ago

Answer this Question

Paul

Top 10

Over 6 months ago

A: The FMF Factory 4.1 Dual RCT Complete Exhaust W/ Stainless Megabomb is approved by the AMA. FMF does not have an FIM approval, but the AMA requirements are the same as the FIM.

To help us to find the correct parts, we will need to know the year, make, and model of your motorcycle.
Depending on the bike for which it is intended, the rear opening of the FMF 4.1 muffler can be between 1 1/4" to 1 5/8" / or 31.75mm to 41.275mm.

I regret that I don't know if the number 0.023 you referred to is inches, feet, millimeters, centimeters or a meter. 0.023 if an inch is less than the thickness of a sheet of paper. 0.023 of a millimeter is less than the thickness of a hair. 0.023 of a meter, or 2.3 centimeters, is less than one inch.

Rick922

Q: Mapping

1 year 11 months ago

I'm interested in installing this system on my 2017 cry 450r, will I have to get the ecm remapped to run properly? Worried about a lean running bike and deceleration backfire along with higher cylinder temp, burnt valves

Answer this Question

Alex

Top 25

1 year 11 months ago

A: Fuel injected bikes will still run properly and see some of the available benefit after installing an exhaust system on them. If you want to get the most power and benefit from the exhaust system (and other motor upgrades) it is always recommended to get a tuning tool and remap the ECU.

yovas

Q: Does it fit on a 2015 raptor 700r se or is their any full exhust systems for this year and model atv

Over 4 years ago

Answer this Question

MotoSportExpert

Top 10

Over 4 years ago

A: No, this FMF system is for dirt bikes. We have HMF, Yoshimura and Big Gun available for your Raptor 700.

Just be sure to correctly select the Year/Make/Model of your ATV before ordering so we can be sure to send you the correct product for your ATV. Also, feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.

molson621

Q: Does this system (FMF Factory 4.1 RCT Complete Exhaust With Stainless Megabomb Header - Dual) come with spark arrestors?

Over 5 years ago

Answer this Question

MotoSportGrantK

MotoSport Staff

Over 5 years ago

A: Yes, spark arrestor screens are included.

Philip

Q: What is the db measured at without the quiet insert? is it difficult to remove?

Over 6 years ago

Answer this Question

MotoSportExpert

MotoSport Staff

Over 6 years ago

A: This will be a 98 dB system without the quit core installed and a 94 dB system with it installed. The quite cores are held in with one bolt on the bottom of the exhaust tip. Very quick and easy installation and removal.

yz250

Q: How easy is it to remove the spark arrester? Do I need to drill out rivets or is it as easy as unscrewing a screw?

Over 6 years ago

Answer this Question

MotoSportExpert

MotoSport Staff

Over 6 years ago

A: There will be no drilling required to remove the spark arrestor screens. A single screw is all that holds them in.

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See Fitments

Product Variant	Manufacturer Part #
Aluminum	041531
Titanium	041551

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.

FMF Factory 4.1 Dual RCT Complete Exhaust W/ Stainless Megabomb

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