Exhaust› Mufflers and Resonators

FMF

Factory 4.1 RCT Titanium Slip-On Muffler

$649.99

SKU: 045586

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The FMF Factory 4.1 RCT is a slip-on muffler designed for 4-stroke dirt bikes. It features FMF's Resonance Chamber Technology for improved performance and a shorter overall length that makes it less susceptible to damage. Constructed from aerospace-grade titanium with a blue anodized finish and a carbon end cap, this muffler is manufactured in Southern California.
Show original supplier description
The FMF Factory 4.1 RCT is a slip-on muffler engineered to deliver significant performance enhancements for your 4-stroke dirt bike. It incorporates FMF's advanced Resonance Chamber Technology, both internally and externally, to optimize power delivery throughout the RPM range. The design prioritizes mass centralization by moving the muffler closer to the motor, complemented by a shorter overall length that increases resistance to crash damage. It is manufactured entirely at FMF's Southern California facility. The system includes a screen insert spark arrestor and a quiet insert, offering versatility for different riding conditions. This slip-on muffler offers massive power gains and significant weight savings compared to stock components. It also incorporates FMF's new RTS (Rapid Tuning System). Please note that this product is intended for closed course use only. Header compatibility should be verified separately.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandFMF
Part Number045586
CategoryExhaust
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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