The FMF Q4 Hex Spark Arrestor Exhaust Muffler, manufacturer part number 044442 and vendor part number 79-4173, is designed for select Yamaha four-stroke motocross and off-road motorcycles. This performance muffler uses internal baffles, chambers, and advanced sound-absorbing materials to promote efficient exhaust flow while controlling noise and minimizing power loss. Its compact design provides a practical replacement or upgrade for riders who need dependable exhaust performance and responsible sound output.
The integrated U.S. Forestry-approved spark arrestor helps support compliant off-road operation, while the maintenance-free stainless steel spark arrestor screen is built for long-term use with minimal service requirements. The FMF Q4 Hex is engineered to remain well below the 96 dB sound limit on most machines, helping it meet strict sound requirements when properly installed and used with a compatible motorcycle configuration.
Fitment includes the 2018 Yamaha YZ450F; 2019 Yamaha YZ450F, YZ450FX, and WR450F; 2020 Yamaha YZ450F and YZ450FX; 2021 Yamaha YZ450F and YZ450FX; and 2022 Yamaha YZ450F and YZ450FX. Verify the model year and motorcycle configuration before ordering. This FMF exhaust muffler is supplied as a vehicle-specific component for the listed Yamaha models and is intended to provide controlled sound, efficient exhaust flow, and spark-arresting capability for appropriate riding environments.
Features:
- Exhaust flow: Internal baffles, chambers, and advanced sound-absorbing materials help accelerate exhaust flow with less noise and minimal power loss.
- Sound control: Designed to operate well below the 96 dB sound output requirement on most compatible machines.
- Spark arrestor: U.S. Forestry-approved spark arrestor supports responsible off-road use.
- Screen construction: Maintenance-free stainless steel spark arrestor screen provides durable, low-maintenance service.
- Fitment: Fits 2018 Yamaha YZ450F; 2019 Yamaha YZ450F, YZ450FX, and WR450F; 2020 Yamaha YZ450F and YZ450FX; 2021 Yamaha YZ450F and YZ450FX; and 2022 Yamaha YZ450F and YZ450FX.
- Identification: FMF manufacturer part number 044442 and vendor part number 79-4173.
Fitment:
2018 Yamaha YZ450F
2019 Yamaha WR450F
2019 Yamaha YZ450F
2019 Yamaha YZ450FX
2020 Yamaha WR450F
2020 Yamaha YZ450F
2020 Yamaha YZ450FX
2021 Yamaha WR450F
2021 Yamaha YZ450F
2021 Yamaha YZ450FX
2022 Yamaha WR450F
2022 Yamaha YZ450F
2022 Yamaha YZ450FX
2023 Yamaha WR450F
2023 Yamaha YZ450F
2023 Yamaha YZ450FX
2024 Yamaha WR450F
2024 Yamaha YZ450F
2024 Yamaha YZ450FX
2025 Yamaha WR450F
2025 Yamaha YZ450F
2025 Yamaha YZ450FX
2026 Yamaha WR450F
2026 Yamaha YZ450F
2026 Yamaha YZ450FX