Brought my 2003 yz125 back to life!!! Great throttle response and more low end.
Boyesen's revolutionary dual-stage reed design delivers more usable power than stock. Your original one-stage reed operates most effectively only within a narrow RPM range. 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.