Boyesen 616 Power Reed For: Husqvarna 400 H2O through 1998; Husqvarna 430 Auto 1985-1988; Husqvarna 430 H2O through 1998; Husqvarna CR250 and WR250 1982-1988; Husqvarna CR500 and WR500 XC 1982-1988 Power reeds use a patented dual stage fiberglass design for more air flow, more air velocity and more power 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 Longer overall life: Boyesen power reeds outlast all other aftermarket reed petals Minor change gives major horsepower improvements and fuel economy