The FMF Racing Factory 4.1 RCT Stainless Slip-On with Carbon End Cap is engineered for discerning riders, featuring advanced FMF Resonance Chamber Technology™ to enhance power and centralise mass. This slip-on exhaust, crafted from aerospace-grade materials, offers substantial power and weight advantages, a short profile to reduce crash vulnerability, and FMF’s innovative Factory Forward Engineering. Built with a natural aluminium muffler, stainless steel mid-pipe, and striking carbon end cap, the Factory 4.1 RCT is designed and manufactured in Southern California to exacting standards.

Features

• Closed course use only
• Advanced FMF Resonance Chamber Technology™
• Compact design helps avoid crash damage
• Natural aluminium muffler with carbon fibre end cap
• Aerospace-grade construction for high durability
• Significant power increase across the RPM range
• Substantial weight savings
• Includes Rapid Tuning System (RTS) for easy adjustments
• Spark arrestor screen insert included
• Quiet insert available separately (not included)
• Manufactured exclusively in FMF’s Southern California factory

Specifications

• Type: Slip-On
• Configuration: Single
• Construction: Aluminium
• Finish: Natural
• Midpipe: Stainless Steel
• Endcap: Carbon
• Spark Arrestor: Screen insert (included)
• Weight: 5.2 lbs
• Item ID: 044406

Vehicle Fitment

Yamaha

• WR450F (2016–2018)
• YZ450F (2014–2017)
• YZ450FX (2016–2018)