Factory 4.1 RCT Exhaust Silencer 09-11 Kawasaki KX 450 F - FMF 042291
4.1 Trustpilot 99.9% positive on eBay
Free UK delivery 2–4 business days
Spread the cost with 
18+, T&Cs apply
The Factory 4.1 RCT Stainless SL Slip-On with Carbon End Cap delivers advanced performance with FMF’s Resonance Chamber Technology optimizing power output and mass centralisation. Built from aerospace grade materials, this slip-on exhaust offers substantial weight savings, improved crash resilience and the Rapid Tuning System for seamless adjustments. Its precise engineering ensures reduced overall length and an optimally positioned muffler for enhanced handling and durability. Features include internal and external FMF Resonance Chamber Technology, a shorter forward-positioned muffler design for centralised mass and reduced crash vulnerability, and construction from aerospace grade aluminium and stainless steel with a carbon fibre end cap. It provides massive power gains across the RPM range and significant weight reduction over stock systems. The natural aluminium finish with carbon end cap offers strength and style. A screen-type spark arrestor insert and 94dB quiet insert are included. Manufactured 100% in FMF’s Southern California factory. For closed course competition use only. Item ID: 042291. Type: Slip-On. Configuration: Single. Construction: Aluminium. Finish: Natural. Midpipe: Stainless steel. Endcap: Carbon fibre. Spark Arrestor: Screen insert (included). Quiet Insert: 94dB insert (included). Weight: 5 lbs approximate.
- SKU
- 06-1754.FMF.FAC
- Brand
- FMF Exhausts
- Availability
- In Stock (1)
Fitments (3)
| Make | Model | Year |
|---|---|---|
| KAWASAKI | KX 450F | 2009 |
| KAWASAKI | KX 450F | 2010 |
| KAWASAKI | KX 450F | 2011 |
- General Product Group
- Exhaust Systems & Parts
- General Product Type
- Silencer
- Variant Id
- 209300
FULL DESCRIPTION
FMF Factory 4.1 RCT Slip-On Exhaust with Carbon End Cap
Experience peak performance with the FMF Factory 4.1 RCT Stainless SL Slip-On Exhaust System. Engineered with FMF’s advanced Resonance Chamber Technology™, this system is designed to optimize power output and centralize mass, making it ideal for professional racing applications. Constructed in FMF's Southern California facility using premium, aerospace-grade materials, this slip-on offers significant weight savings and enhanced durability. The innovative Rapid Tuning System allows for straightforward adjustments, while the shorter, forward-positioned muffler design improves handling and reduces vulnerability during impacts.
Key Features:
- Features both internal and external FMF Resonance Chamber Technology™ for optimized performance.
- Muffler is shorter and positioned more forward, centralizing mass and improving crash resilience.
- Constructed from aerospace-grade aluminum and stainless steel with a stylish carbon fiber end cap.
- Delivers substantial power gains across the entire RPM range.
- Offers a significant reduction in weight compared to stock exhaust systems.
- Equipped with the Rapid Tuning System (RTS) for quick and easy adjustments.
- Natural aluminum finish with a carbon fiber end cap provides durability and a high-performance aesthetic.
- Includes a screen-type spark arrestor insert and a 94dB quiet insert.
- Proudly manufactured 100% in FMF’s Southern California factory.
- This product is intended for closed course competition use only.
Specifications:
- Type: Slip-On
- Configuration: Single
- Construction Material: Aluminum
- Finish: Natural
- Midpipe Material: Stainless steel
- Endcap Material: Carbon fiber
- Spark Arrestor: Screen insert included
- Quiet Insert: 94dB insert included
- Approximate Weight: 5 lbs
QUESTIONS? JUST ASK
Talk to John or Phil. Real people, Monday to Friday, 10:00 to 17:00.
Check the fitment table on this page against your make, model and year. Not sure? Call or email us and we will check it for you before you order.
UK delivery is £4.99, or free on orders over £60. Orders ship within 3 working days, then delivery takes 2–4 business days. Delivery details
Yes. You have 14 days from delivery to return it, unused and in its original packaging. Contact us first and we will send you the return instructions. Returns policy
By card, PayPal, Apple Pay or Google Pay, or spread the cost with Klarna. Payment is taken securely by Stripe, and the options for your order are shown at checkout.
More answers in our FAQ.
Trade pricing available
Buying parts for your business? Apply for a 2BrosParts trade account.