Boyesen Power Reed Dualstage Yamaha Tdr125, Tzr125 91-4 Polisport New Upload An additional inner sleeve provides

An additional inner sleeve provides the knee with additional support and stability

You want more

390 RR 17-23

or 15cm (6 inch)

New smaller back for better fit

Boyesen Power Reed Dualstage Yamaha Tdr125, Tzr125 91-4 Polisport New Upload An additional inner sleeve providesOne reed petal is NOT enough! 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.