What is the Power Bomb module and what does it do?

The Power Bomb module is a patented component integrated into the header system. It functions as a pre-muffler, helping to increase exhaust flow by nearly 10% and absorb sound waves to reduce the overall noise output of your motorcycle.

How does this muffler help reduce sound?

The muffler uses a perforated core that allows exhaust gases and sound waves to pass into the steel wool packing. This process absorbs sound energy and helps to cool the gases, resulting in a quieter exhaust note compared to a stock system.

Does this muffler come with a new header pipe?

This product is a muffler designed to attach to your existing header system. It does not include a new header pipe.

Specifications

Brand: FMF Racing
Part #: 044199

FMF Racing Yamaha YZ450F 03-05/WR450F 03-06 Q4 S/A Muffler

Name: FMF Racing Yamaha YZ450F 03-05/WR450F 03-06 Q4 S/A Muffler
Brand: FMF Racing
SKU: fmf-racing-fmf-racing-yamaha-yz450f-03-05-wr450f-03-06-q4-s-a-muffler-t14-686924
Price: 495.35 USD
Availability: BackOrder

$495.35

On Backorder — Expected to ship by Apr 28, 2026

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

FMF Racing Q4 S/A Muffler for Yamaha YZ450F 03-05/WR450F 03-06. Features Power Bomb module for improved flow and sound reduction.

Key Features

Fits Yamaha YZ450F 2003-2005 and WR450F 2003-2006.
Incorporates FMF's patented Power Bomb module for improved exhaust flow.
The Power Bomb module acts as a pre-muffler to help reduce sound output.
Perforated core design allows sound absorption into steel wool packing.
Designed to work with your existing header system.

This muffler is designed to fit the Yamaha YZ450F from 2003-2005 and the WR450F from 2003-2006. Please confirm compatibility with your specific model year.

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About this part

Product Details

If you're looking to get more out of your Yamaha YZ450F (2003-2005) or WR450F (2003-2006) exhaust system, this FMF Racing Q4 S/A muffler is a solid option. It's designed to work with your existing header system, and it incorporates FMF's patented Power Bomb module right at the start of the header.

This Power Bomb module acts like a pre-muffler. By strategically placing it, FMF has created a system that increases exhaust flow by nearly 10%. The perforated core inside the muffler allows sound waves to exit into the steel wool packing, where they are absorbed. This expansion and contraction process helps to lower the overall sound output of your bike, making it quieter without sacrificing performance. The result is a well-built muffler that offers improved flow and a more controlled sound.