Factory 4.1 RCT Slip-On Muffler

The FMF Factory 4.1 RCT Slip-On Muffler is designed for riders who want performance gains without excessive noise. Its patented RCT (Resonance Chamber Technology) core shape helps lower decibels while still maintaining maximum power output, making it a smart upgrade for track days, trails, and organized events with sound limits.

If you’re dealing with a muffler that’s too loud for regulated riding areas—or you want a cleaner, stronger pull across the rev range—the RCT internal chamber design increases volume and improves exhaust flow for power gains throughout the entire powerband. FMF’s Factory Forward Engineering also centralizes mass, helping reduce the chance of crash damage compared to more exposed designs.

Key features:

• ✅ Patented RCT core shape lowers dB while maintaining maximum power output
• ✅ Internal RCT ducts increase volume for improved flow and broad power gains
• ✅ Factory Forward Engineering centralizes mass and helps reduce crash damage risk
• ✅ Rear end cap allows quick tuning tip or spark arrestor changes with four screws
• ✅ Meets AMA and FIM sound requirements

Benefits of use:

• 🔹 More controlled sound levels without giving up performance
• 🔹 Improved throttle response and power across the range thanks to better flow
• 🔹 Practical, service-friendly design for fast changes and easier setup tuning

Technical specifications (when relevant):

• 📌 Type: Slip-On muffler
• 📌 Included: QuietCore 94dB insert, spark arrestor
• 📌 Material: Aluminum canister
• 📌 End cap material/style: Carbon fiber, conical
• 📌 Color/finish: Black (muffler and end cap)
• 📌 Compliance: AMA & FIM sound requirements
• 📌 Made in: U.S.A.

Why choose this product?

• ⭐ Proven FMF Factory-series performance with noise-reducing RCT technology
• ⭐ Includes the parts riders often need (QuietCore insert + spark arrestor) right out of the box
• ⭐ Easy-to-service end cap design for quick tuning and maintenance