The FMF Q4 Slip-On Muffler features advanced engineering to precisely locate baffles and chambers to absorb sound while delivering quiet power with minimal sacrifice for performance.
Developed over years of championship off-road racing, this muffler utilizes less mass to enhance your bike's power-to-weight ratio and includes a twin-stage core design for lower sound output and extended packing life.
Top Features: FMF Q4 Slip-On Muffler
Advanced engineering precisely locates baffles and chambers to absorb sound.
Less mass enhances your motorcycle's overall power-to-weight ratio.
Engineered to deliver quiet power with minimal sacrifice for performance.
Twin-stage core design lowers sound output and extends the life of packing material.
Comes standard with an integrated spark arrestor for trail compliance.
Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.
Fitment List
Year Range
Vehicle Brand
Vehicle Model & Sub-Model
2003-2006
Yamaha
WR450F
2003-2005
Yamaha
YZ450F
Frequently Asked Questions
Q: Does this slip-on muffler include a spark arrestor? A: Yes, it comes standard with an integrated spark arrestor for legal off-road and trail riding.
Q: Will this muffler reduce my bike's sound level without losing power? A: Yes, the advanced baffle design and twin-stage core lower sound output while maintaining strong, race-developed performance.
Expert Pro-Tip: Inspect your muffler packing every 20-30 hours of riding and repack when necessary using high-quality packing material to maintain legal sound levels and prevent power loss.
At Moto-House MX, we carry the best brands in motocross and off-road performance. Our team has over 40 years of experience helping riders get more out of their bikes. We pride ourselves on great customer service, and every item ships FAST - straight to your door.
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