Full Exhaust System FMF Factory 4.1 RCT — Honda CRF 450 R, CRF 450 RX 2021–2026 (4T)

The FMF Factory 4.1 RCT is FMF's flagship four-stroke silencer. RCT (Resonance Chamber Technology) is a patented core shape that pulls the noise down while keeping the power up — so you can ride where the decibels get measured without giving up performance. Internal ducts in the chambers increase volume and improve flow, so power rises across the whole rev range. Factory Forward Engineering centralises mass, which helps handling and reduces crash damage. The rear end cap opens with four screws — you swap a tuning insert or spark arrestor without taking the silencer off. Works with the stock header or an FMF one. Fits: Honda CRF 450 R (2021–2026); Honda CRF 450 RX (2021–2026). Specifications — muffler material: Aluminum, pipe material: Stainless Steel, material: Aluminum, Carbon Fiber, Stainless Steel, muffler finish: Natural, configuration: Single Canister. Note: does not meet the 2025 FIM sound limit — intended for practice and closed courses, not for FIM-sanctioned racing. QuietCore 94 dB insert included. Delivery 5–8 working days. SKU: 041604.