Boyesen's patented dual-stage reed 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.
Fits: Yamaha IT175 1977-1981 IT200 1984-1986 YZ125 1980-1987 1993