FMF Q4 HEX S/A 045667 Muffler — Quiet, High-Performance Slip-On for ATV and Dirt Bike

FMF’s Q4 HEX S/A 045667 slip-on muffler is built for off‑road riders who want power without a loud exhaust note. The design uses intricate chambers, baffles, and proprietary multistage packing material to achieve quieter operation while preserving strong performance. This muffler flows exhaust efficiently, delivering horsepower and torque gains across the engine’s RPM range.

• Spark arrestor included for safe, trail-ready use.
• Pounds lighter than stock, contributing to improved handling and agility.
• Rugged, durable construction designed for off‑road endurance.
• Meets USFS and FIM World Enduro sound regulations for mixed terrain riding.
• Made in the USA by FMF, the leader in dedicated quiet exhaust technology.
• Easy installation with standard tools; designed to complement FMF’s quiet, performance-focused philosophy.

The Q4 HEX series represents FMF’s ongoing evolution of quiet performance, offering a distinct exhaust note and improved flow that many riders notice in real-world riding scenarios—from trail climbs to fast open sections. Part number 045667 identifies this slip-on setup, purpose-built to upgrade your exhaust system without sacrificing reliability or durability.

FMF is the leader in high performance quiet technology and our Q4 HEX is the next evolution in off road exhaust. The Q4 employs intricate chambers, baffles and proprietary multistage packing material making it the best performing quiet muffler available. With the Q4 you don’t need to hear the power, just feel the power!

-Less sound equals more ground

-Meets USFS and FIM World Enduro sound regulations

-Power gains throughout the entire rpm range

-Spark arrestor included

-Pounds lighter than stock

-Rugged design for off-road endurance

-Only US manufacturer to offer dedicated quiet exhaust systems

-MADE IN THE USA

Upgrade your vehicle's exhaust system with the FMF Racing Q4 Muffler, part number 045667. Designed for enhanced performance and durability, this muffler delivers improved exhaust flow and a distinctive sound that enthusiasts appreciate. Constructed with high-quality materials, the FMF Q4 Muffler ensures long-lasting performance in demanding riding conditions. Its sleek design not only boosts power but also complements your vehicle's aesthetic appeal.
The FMF Racing Q4 Muffler features a lightweight yet robust construction, making installation straightforward and reducing overall vehicle weight for better handling. Its proven design helps optimize exhaust gas flow, resulting in increased horsepower and torque across a wide range of engine speeds. Whether you're racing or trail riding, this muffler provides reliable performance and a noticeable upgrade over stock components.
Suitable for a variety of off-road vehicles, the FMF Q4 Muffler is an excellent choice for riders seeking improved sound, performance, and durability. Easy to install with standard tools, it is the perfect addition to your maintenance or upgrade plan, ensuring your vehicle performs at its best on every ride. Trust FMF Racing's reputation for quality and innovation to enhance your riding experience with this high-performance muffler.

Features:

• Enhanced exhaust flow for increased horsepower and torque

• Durable construction with high-quality materials

• Lightweight design reduces overall vehicle weight

• Sleek and functional aesthetic appeal

• Easy to install with standard tools