
FMF
Factory 4.1 RCT Slip-On Muffler - Titanium with Carbon Fiber End Cap - YZF450F/FX
Part # 1821-1840
$849.99
In Stock
- 60-day returns
- Free shipping over $100
- Secure checkout
CA Prop 65 Warning: WARNING:
Confirmed fit for 22 motorcycle configurations across Yamaha, model years 2018–2026.
| Years | Make & Model |
|---|---|
| 2019-2025 Yamaha | YZ450FX |
| 2018-2026 Yamaha | YZ450F |
| 2019-2024 Yamaha | WR450F |
- RCT (Resonance Chamber Technology) features a patented core shape that lowers decibels while maintaining maximum power output
- Internal ducts in the chambers of the RCT system increase internal volume for improved exhaust flow, resulting in power gains throughout the entire range of power
- FMF's Factory Forward Engineering centralizes mass and is less prone to crash damage
- Innovative rear end cap features simple installation of tuning tip inserts or spark arrestor with the removal of four screws
- Compatible with stock header or FMF header
- Meets AMA and FIM sound requirements
- QuietCore 94 dB insert included
- Spark arrestor included in muffler
- Made in the USA
Customer Reviews
No reviews yet — be the first to review this part.
Overview
The FMF 1821-1840: Factory 4.1 RCT Slip-On Muffler - Titanium with Carbon Fiber End Cap - YZF450F/FX. Confirmed fit for 22 motorcycle configurations across Yamaha, model years 2018–2026. Ships from Greasemoto — a veteran-owned motorcycle parts shop in Fort Worth, TX — with free U.S. shipping on orders over $100.
More from FMF

FMF
FMF12-002
Muffler Packing - 2-Stroke
$10.99

FMF
1860-0828
Pillow Muffler Packing - 4-Stroke
$31.99

FMF
FMF011231
Puller Tool - Exhaust Spring - T-Handle - Black
$15.99

FMF
1861-0585
Wash Plug - 2-Stroke
$5.99

FMF
25014693
Machinist Hat - Black
$32.00

FMF
1820-0175
Factory Fatty Pipe
$329.99

FMF
2501-4537
Powerhouse Hat - Black
$34.00

FMF
1820-0739
Powercore 4 Exhaust
$279.99
