BOYESEN Racing Reed - Yamaha 604

Your engine's intake system is only as efficient as its reed valves—and stock reeds are holding back your Yamaha 604's potential. Boyesen's dual-stage reed design delivers measurably higher flow velocities across the entire pressure curve, translating directly to sharper throttle response and stronger acceleration from idle to peak RPM. If you're serious about extracting every ounce of performance from your engine, upgrading to a proven reed design backed by laboratory flow analysis is a no-brainer.

The Boyesen Racing Reed outperforms standard reeds through a sophisticated two-stage geometry that maintains optimal flow characteristics whether you're at start-up or pushing maximum load. This isn't theoretical—the engineering is proven through rigorous testing and validated by professional racers and demanding DIY builders alike.

• Dual-stage reed design
• Optimized flow geometry
• Laboratory-tested performance
• Fits Yamaha 604
• Bolt-on installation
• Improves throttle response
• Enhanced acceleration range
• OEM replacement compatible