The Buckshot Racing #77 Carburetor Velocity Stacks are engineered for high-performance marine applications, particularly designed for Mercury Racing V6 outboard engines.
Manufactured from precision-machined 6061-T6 billet aluminum, these velocity stacks offer a significant improvement in airflow dynamics over traditional cast components.
The optimized bell-mouth design facilitates smoother and faster air intake, enhancing throttle response, air-fuel mixture efficiency, and overall horsepower.
Design Features That Enhance Performance
Proprietary Overcut Geometry: Provides stable atmospheric pressure delivery to the idle circuits, improving low-end performance.
Dual-Air Sharing Bridge: A built-in bridge design enables adjacent carburetors to share intake airflow, promoting balanced fuel delivery.
The Buckshot #77 Velocity Stacks are direct-fit replacements for the discontinued Mercury Racing cast aluminum one-piece CARB PLATE ASSY, OEM Part #13443A1 (MSRP $279).
These intake plates replaced the sound attenuator air box on high-performance performance outboard models including the SST-120, SST-140, Formula 1 (USF1), APBA F200, and various 2.0L, 2.4L, and 2.5L race-class motors found in UIM, APBA, and OPC competition series.
Wide Compatibility: 1976–2005 Mercury V6 2-Stroke Carbureted Engines
These stacks are compatible with all carbureted Mercury V6 outboards featuring WH, WMV, or WMH carburetors, spanning model years from 1976 to 2005. Supported engine families include:
Mercury 135, 150, 175, 200, 225 HP (2.4 Liter), 245 HP (2.5 Liter)
Mercury Black Max, XR2, XR4, and XR6 outboards
Race SST-140 WH-31, SST-120 WH46 and WMV-5
All Mercury V6 2-stroke 2.0L & 2.4L vertical and horzontal front halves
All Mercury V6 2-stroke 2.5L outboards
All Mercury 3.0L V6 carbureted models
Upgrades Bob's Machine Shop Cast Velosity Stacks
By replacing the restrictive stock airbox, the #77 stacks enable increased volumetric efficiency and more consistent fuel atomization, especially at high RPMs.
Modular Design for Easier Maintenance
Unlike the OEM integrated carb plate, Buckshot's modular stack system includes separate mounting plates, allowing technicians easier access during jetting and carburetor removal. This feature streamlines tuning and servicing for professional and amateur engine builders alike.
Surface Finish & Color Options
Each set of three (3) Buckshot Racing #77 Velocity Stacks is glass-bead blasted to remove surface impurities and then anodized for corrosion resistance and durability. Color options include red, black, and blue, each suitable for harsh racer and marine environments.
Center Pull Carb Caps (Optional): Keep your motor clean and running strong by reducing possible dust dirt, and sand injection during trailing and storage with Buckshot's optional center pull linkage caps.
This kit is designed for performance enthusists and racaers who demand top-tier parts, best quality, and are looking to improve legacy 2-stroke outboard performance.
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com for technical support.
7 disciplines we employ on every Billet part!
1. We select and use high-quality cutting tools designed for aluminum machining to minimize tool wear and achieve a smooth finish.
2. We work to optimize speeds and feeds, adjusting cutting speeds and feed rates to achieve the optimal balance between material removal and surface finish.
3. We employ coolant or lubricant to dissipate heat and reduce friction during machining, which helps prevent tool overheating and improves surface finish.
4. We ensure our tool runout is minimized to reduce vibration and chatter, which can negatively impact surface finish.
5. We implement proper tool paths including climb milling, to minimize tool deflection and achieve a better surface finish.
6. We perfect ramping, profiling, or contouring to find the most suitable approach for each part.
7. We properly calibrate and align our CNN machines to achieve accurate cuts, which enhances surface finish. This includes inspecting and maintaining utilized CNC machines and tooling to ensure optimal machining every run.
These best practices have helped us enhance the precision and the surface finish of our Buckshot Racing #77 Speed Store CNC machined 6061 aluminum billet parts, to the highest level.