FMF - Q4 Hex Slip-On Muffler (Yamaha)

FMF - Q4 Hex Slip-On Muffler (Yamaha)

If you want more power without blowing out your eardrums or breaking sound limits, the FMF Q4 Hex Slip-On is the answer. FMF has led the way in quiet exhaust tech for years, and the Q4 is their best version yet — a system that lets you feel the power without having to hear it. Designed with a series of internal chambers, baffles, and FMF’s proprietary multi-stage packing, it keeps the decibels down while still delivering strong, usable gains across the entire rev range.

Built from tough materials and designed to handle rough off-road conditions, the Q4 gives your Yamaha smoother throttle response, more torque, and a deeper, refined tone that sounds clean without being loud. It’s lightweight, durable, and fully trail-legal — the kind of upgrade you can trust season after season.

Why We Like It:
It’s quiet but it rips. The Q4 gives you noticeable power gains and better throttle control, all while keeping your sound levels trail-friendly. It’s perfect for riders who want real performance without annoying the neighbors or catching flak from the rangers.

Why It’ll Work for You:
This muffler improves your Yamaha’s low-end torque and midrange pull — right where you need it most when climbing, cornering, or working through tight sections. The tuned chambers and packing reduce sound while helping the motor breathe freely, so you get more traction and smoother power delivery. And because it meets USFS and FIM sound rules and comes with a spark arrestor, it’s ready for any trail system straight out of the box.

Key Features:

• 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