FMF Q4 — Yamaha YFZ450R (2009-2026), Yamaha YFZ450X (2010-2011), 4-Stroke

The Q4 is FMF's quiet 4-stroke slip-on — engineered to lower sound levels without giving up horsepower. Internal chambers, baffles, and proprietary multi-stage packing material drop most models below 93 dB with a max of 96 dB. Pounds lighter than stock, with a built-in spark arrestor and easy repack.

• Quiet 4-stroke slip-on — max 96 dB, most models below 93 dB
• Internal chambers and baffles with multi-stage packing
• Built-in spark arrestor
• Pounds lighter than stock
• Compatible with stock or FMF header
• Easy to repack

This is a 4-stroke exhaust. It is engineered for the 4-stroke engine architecture above and physically will not fit a 2-stroke bike. Verify your engine type before purchase.