FMF Factory 4.1 RCT Slip-On Muffler 045633 — Gas Gas / Husqvarna / KTM 250cc 2019-2023

Product Description

The FMF Factory 4.1 RCT Slip-On Muffler represents the pinnacle of exhaust engineering for your motocross or off-road bike. Built with FMF’s patented Resonance Chamber Technology (RCT), this muffler utilizes a unique core shape that effectively lowers decibel levels without sacrificing raw power. The result is a substantial increase in power throughout the entire RPM range, giving you the competitive edge you need on the track.

Designed with FMF's signature Factory Forward Engineering, this muffler helps centralize mass, improving your bike’s handling while remaining significantly more resistant to crash damage. Whether you are racing professionally or hitting the trails, this blue anodized titanium muffler with a premium carbon fiber end cap offers unmatched durability, performance, and style.

Top Features: FMF Factory 4.1 RCT Slip-On Muffler

• Resonance Chamber Technology reduces decibels while maximizing overall power output.
• Factory Forward Engineering centralizes mass for improved bike handling and durability.
• Carbon fiber end cap design allows for quick installation of tuning tips or spark arrestors.
• Includes QuietCore 94 dB insert and spark arrestor for versatility in racing and off-road riding.

Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.

Fitment List

Frequently Asked Questions

Q: Will this fit my stock header pipe?
A: Yes, this FMF Factory 4.1 RCT slip-on is designed to be compatible with your stock header or an FMF aftermarket header.

Q: Does this muffler meet race sound regulations?
A: Absolutely. It is designed to meet both AMA and FIM sound requirements, and it even includes a QuietCore 94 dB insert for sensitive riding areas.

Expert Pro-Tip

Expert Pro-Tip: Don't forget to keep your exhaust packing fresh! A high-performance pipe like this will lose its power gains and start sounding harsh if the packing is blown out. I recommend repacking your muffler every 10–15 hours of hard riding to keep the bike pulling strong and quiet. Also, whenever you install a new slip-on, reset your ECU or check your fuel mapping—a slight lean condition can negate the power gains of your new pipe.

Recommended Pairings

Recommended Pairings:
o KTM 250 SX-F Performance Parts & Upgrades
o Husqvarna FC 250 Performance Parts
o Gas Gas MC 250F Performance Parts

About Moto-House MX

At Moto-House MX, we carry the best brands in motocross and off-road performance. Our team has over 40 years of experience helping riders get more out of their bikes. Every order ships fast from our Central Florida location.

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