The Buckshot Racing #77 Boyesen 4-Petal Dual-Stage Reed Kit is a high-performance replacement for compatible Mercury and Mercury Racing four-petal reed cages, including applications associated with Mercury OEM 855952 and 855952T3.
Originally used in high-RPM Mercury racing induction systems, this four-petal design is also an excellent upgrade for compatible Mercury 2.5L 150 HP, XR6 150 and 200 EFI outboards. It is also commonly associated with SST-120, S2000, Formula 2, European XR2 and custom Mercury Racing V6 engines using the correct four-petal cage.
Boyesen’s Dual-Stage design uses two composite reed elements with different stiffness levels. The lighter upper reed reacts quickly at lower airflow demand, while the firmer lower reed provides additional flow and stability as RPM increases. This helps improve throttle response, acceleration, intake velocity and high-RPM airflow control across a broader powerband.
Replaces Mercury Racing 14594A3 Reed Assemblies
The Boyesen four-petal kit replaces discontinued Mercury Racing reed assemblies commonly referenced as 34-14594A3, 3414594A3 and 14594A3.
These part numbers are important for racers and restorers maintaining older Mercury Racing powerheads. The Boyesen kit provides a modern composite replacement while retaining compatibility with the corresponding Mercury four-petal reed-cage design.
Fitment should always be confirmed by reed-cage part number, petal count and front-half configuration, not horsepower or engine decal alone.
Mercury Marine & Mercury Racing Applications
This kit is intended for compatible Mercury V6 engines using the 855952 / 855952T3-style four-petal reed cage.
Common applications include Mercury 150 HP 2.5L, XR6 150, 200 EFI 2.5L, along with SST-120, S2000, Formula 2, European XR2 and custom Mercury Racing V6 powerheads using the same induction system.
This makes the kit useful both as a replacement for discontinued Mercury Racing reeds and as a performance upgrade for compatible production Mercury 2.5L V6 engines.
Because many Mercury V6 engines have been modified or rebuilt, inspect the actual reed cage before ordering.
Why Dual-Stage Reeds Work
At high RPM, reed petals open and close hundreds of times every second. Their stiffness, weight and sealing quality directly influence how efficiently the crankcase fills.
Boyesen’s softer primary reed responds quickly for crisp throttle response, while the firmer secondary reed contributes additional airflow and control as engine speed rises.
The result is improved response across a wider RPM range than a conventional single-stage reed.
Complete Reed Rebuild Package
The Buckshot Racing #77 Boyesen 4-Petal Dual-Stage Reed Kit includes the upper and lower composite reeds, new reed holders or Rev-Strips, installation instructions and Boyesen decals.
The Rev-Strips replace conventional reed stops and allow the reeds to open more freely while still controlling petal movement.
Buckshot Racing #77 Tech Tip
Before installing new reeds, inspect each reed cage for corrosion, nicks, burrs, cracks or previous reed damage. The sealing surface must be clean and flat.
Each reed should sit flat against the cage without visible gaps. Install the hardware evenly and follow the Boyesen instructions for orientation and tightening. Avoid overtightening, which can distort the holder or cage and reduce sealing quality.
The Buckshot Racing #77 Boyesen 4-Petal Dual-Stage Reed Kit replaces discontinued Mercury Racing 34-14594A3 / 14594A3 reed assemblies and works with compatible 855952 / 855952T3 four-petal reed cages. It is also a strong performance upgrade for compatible Mercury 150 HP, XR6 150 and 200 EFI 2.5L V6 outboards, as well as SST-120, S2000, F2 and custom Mercury Racing V6 engines.
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.