One reed petal is NOT enough! The reed petals in all 2 stroke engines take an incredible amount of abuse! At peak RPM, reed petals are opening and closing hundreds of times per second. Over time, a single reed loses its ability to regulate flow rates in proper proportions. This causes a loss of reed petal reaction and reduces the consistency of peak horsepower. Boyesen’s revolutionary dual-stage reed design delivers more usable power than stock. Stock single-stage reeds operate most effectively within a relatively narrow RPM range and are limited because of the single stage design. Boyesen’s one soft reed on top of one firm flow-through reed gives you a wide range of intake control, plus increased intake velocity. Your original reeds can’t possibly duplicate that performance. 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. The multi-port feature of the bottom reed creates more channels for the charge, delivering increased velocity to the intake ports and generating more overall power. Dual-stage reeds work in unison to perform efficiently throughout the entire powerband. 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 powerband.