FMF Factory 4.1 Slip-On Exhaust Yamaha YZ250F / YZ450F 2006-2009 / WR250F 2007-2013 / WR450F 2007-2011

FMF Factory 4.1 Slip-On Exhaust Yamaha YZ250F / YZ450F / WR250F / WR450F

With 30 years of racing experience behind it, the Factory 4.1 muffler takes advantage of everything FMF has learned on the race track. The patented core shape of the Factory 4.1 Slip-On enhances exhaust pressure for optimal power output while keeping sound levels to a minimum. The compact design not only makes this muffler less susceptible to crash damage, but also centralizes mass by keeping the weight of the muffler closer to the motor and center of gravity.

Features:

• Horsepower gains throughout RPM range
• High quality internal packing material for maximum longevity
• 94 dB Insert Included
• Can be used with FMF or Stock OEM Header
• Weight: 5 lbs
• 100% made in the USA