Boyesen reed valve kits will fit Yamaha models below:
1984-1992 - 485 Phazer
1993-1997 - 485 PhazerII,LE,ST
1996-2000 - 485 PhazerII Mtn. Lite
1996-1999 - 485 Venture XL, TR
1999-2000 - 500 Phazer
1982-1992- 540 SR-V
Dual Stage Reeds
- Made with Dura-Flex for superior Strength & flexibility
- Minor change for major HP improvements
- Faster opening and closing
- Greater low-pressure(low throttle) response
- Greater velocity
- Greater flow area
- Longer overall life
- No engine damage if broken
Please be advised that the reed pictures are generic pictures and do not always reflect actual set of reeds.
Free Shipping only applies to US orders.
All kits include enough reed sets for one motor, order one kit for one motor.
Contents: Full set for all cages.
Boyesen's patented dual-stage design incorporates a specially shaped top reed and a ported bottom reed. The top reed is lightweight and resilient for crisp throttle response at partial throttle or low RPMs. The stiffer, bottom reed is ported to provide maximum flow and horsepower at higher RPMs. More valves equals more power by creating:
More Air Flow. The dual-stage design allows you to replace your stock reed stop with a Rev-Plate which permits the reeds to open freely and function efficiently.
More Air Velocity. The multi-port feature of the bottom reed creates more channels for the charge, delivering increased velocity to the intake ports.
More Overall Power. Dual-stage reeds work in unison to perform efficiently throughout the entire power band. The difference in stiffness between the top reed and the bottom reed allow the reeds to respond quickly and accurately to changes in engine pressure. This translates into quicker acceleration, crisper throttle response and increased horsepower throughout the power band.