FMF Factory 4.1 blue anodized titanium silencer with stainless steel link pipe Yamaha YZ 450 F 06-09

Factory 4.1 muffler available in natural titanium or blue anodized titanium with titanium end caps;
The lightest mufflers available;
Superior power and performance – horsepower improved throughout the rpm range;
Feature exclusive proprietary Chamber Core technology;
Factory Forward Engineering centralizes mass, improves handling;
Made from premium quality American materials;
Customize with performance tuning inserts and spark arrestor module;
Meet AMA sound requirements on most models; inserts available for others.

Made in the U.S.A.

Over the decades, we’ve seen an amazing transformation in the world of motorcycles and ATVs. The progression of the technology is one of the challenges that keeps us going. FMF was there in the days when the singleshock and watercooled engines were huge innovations and we’re glad to be here now for the aluminum chassis and electronic fuel injection. Our goal will never change - take the most advanced machinery to its limit by building the world’s best performing exhausts. And its a fact, we build every exhaust by hand from start to finish right here in the U.S.

At the end of the day, there is always one major force keeping us motivated–throwing a leg over the bike and heading for the trails or the track. The biggest reward for us is knowing we’re helping our customers get the most out of their riding experience. We still ride every chance we get so we never forget why we got into this business in the first place.