Mercury WH Slosh Tube Carburetors | 2.0L, 2.4L & 2.5L V6 Carb Parts, Rebuild Kits & Race Set
- Mike Hill
- 4 days ago
- 4 min read
Mercury WH slosh tube carburetors are a proven performance carburetor setup used on many classic Mercury V6 two-stroke outboards, including 2.0 Liter, 2.4 Liter, and 2.5 Liter applications.
For racers, builders, restorers, and high-performance outboard owners, the WH carburetor remains popular because it is simple, tunable, serviceable, and capable of strong fuel delivery when properly cleaned, rebuilt, jetted, and synchronized.
Buckshot Racing #77 builds, services, and supplies parts for Mercury WH slosh tube carbs, including rebuild parts, jetting components, gaskets, fittings, linkage pieces, slosh tube parts, washers, screws, carb mounting hardware, and race-ready carburetor support parts to keep these classic Mercury V6 carburetors running in top form.
What Makes Mercury WH Carbs Different
Mercury WH carburetors are commonly used as a three-carburetor set on V6 two-stroke outboards, with top, center, and bottom carburetors feeding the engine through the intake system.
These carburetors rely on clean fuel passages, correct float height, proper jetting, tight gaskets, accurate linkage adjustment, and consistent fuel supply to maintain reliable performance.
Unlike modern electronic fuel injection, the WH carburetor system is fully mechanical. That makes it easier to inspect, tune, rebuild, and service, but it also means every passage, jet, gasket, float, needle, seat, fitting, and throttle linkage adjustment matters.
A small fuel restriction, air leak, incorrect jet, or uneven float level can create poor idle quality, hesitation, bogging, lean running, or piston-damaging fuel starvation.
What Slosh Tubes Do
Slosh tubes are used to help stabilize fuel behavior inside Mercury WH carburetors during hard acceleration, rough water, sharp turns, drag racing launches, and high-performance operation.
When fuel moves violently inside the bowl, it can uncover fuel circuits, disturb metering, or create inconsistent delivery. Slosh tubes and related bowl control parts help manage that movement so the carburetor can maintain more consistent fuel metering.
For Mercury Racing and high-performance lake use, this matters because a two-stroke engine depends on proper fuel delivery for both power and piston cooling. A lean condition at high RPM can quickly damage pistons, rings, and cylinders.
Properly built WH slosh tube carburetors help reduce fuel delivery problems caused by bowl movement and can improve throttle response, consistency, and reliability in demanding conditions.
Compatible Mercury V6 Applications
Mercury WH slosh tube carb setups are commonly associated with classic Mercury 2.0L, 2.4L, and 2.5L V6 two-stroke outboard engines. They are used by builders working on Mercury Racing engines, lake racers, Mod-VP style boats, drag boats, tunnel hulls, bass boats, and restored high-performance Mercury outboards.
Because Mercury produced many WH carb variations with different calibrations, stamped numbers, jet sizes, and application-specific setups, carburetors should always be identified before ordering parts or changing jetting.
A WH carb body, throttle linkage, gasket, plate, or jet should be matched to the exact engine combination, fuel system, compression, exhaust, intake, reeds, timing, and intended RPM range.
Common WH Carb Problems
Most Mercury WH carburetors are decades old, and many have seen ethanol fuel, storage varnish, corrosion, worn gaskets, damaged fittings, plugged jets, loose linkage, or previous repairs.
Common problems include hard starting, poor idle, fuel leaks, bogging, hesitation, uneven cylinder fueling, dirty idle circuits, incorrect float height, worn needle and seat assemblies, clogged main jets, cracked or hardened tubing, missing slosh tube parts, and air leaks at the carburetor gaskets or mounting plates.
A proper WH carb rebuild is more than just cleaning the outside. The carburetors should be disassembled, inspected, cleaned internally, rebuilt with correct gaskets and parts, checked for flat sealing surfaces, set for proper float level, fitted with the correct jets, and synchronized so all three carburetors open evenly.
Buckshot Racing #77 WH Carb Parts and Kits
Buckshot Racing #77 offers parts and rebuild support for Mercury WH slosh tube carburetors to help owners keep their carb sets complete, clean, and reliable.
Available parts include carburetor gaskets, slosh tube components, Tygon tubing, elbow fittings, tee fittings, adapter fittings, plugs, tie straps, hoses, linkage kits, throttle levers, rollers, screws, lockwashers, stainless washers, carburetor plate parts, carb mounting screws, and related hardware used in Mercury WH carb service.
Buckshot Racing #77 also supports WH carb tuning with main and idle jet components for builders who need to restore factory-style operation or fine-tune a modified Mercury V6 setup. Correct jetting is critical on any two-stroke outboard, especially on high-performance 2.4L and 2.5L engines where lean running can cause expensive powerhead damage.
Rebuild and Setup Recommendations
A quality WH carb rebuild should begin with clean fuel, clean tanks, fresh fuel lines, a good primer bulb, proper fuel pump function, and clean filters. Rebuilding carburetors without correcting fuel supply problems can lead to repeated contamination and poor performance.
During assembly, every gasket surface should seal correctly, all fittings should be tight, float height should be checked, jets should be verified, and the throttle linkage should be synchronized.
After installation, the engine should be checked for proper idle, clean transition, strong acceleration, fuel leaks, and consistent cylinder temperature or plug readings. On modified engines, jetting should be approached carefully and verified under load.
Why Builders Still Use WH Carbs
Mercury WH carburetors remain popular because they are simple, strong, and highly serviceable. For many racers and Mercury V6 builders, a properly prepared WH carb set offers the mechanical feel, throttle response, and tunability that made classic Mercury performance outboards famous. With the right parts, careful setup, and regular maintenance, WH slosh tube carbs can continue to perform well on 2.0L, 2.4L, and 2.5L Mercury V6 engines.
Buckshot Racing #77
Whether you are restoring a classic Mercury V6, freshening a lake racer, building a 2.5L performance motor, or maintaining a Mercury Racing carb setup, Buckshot Racing #77 can help keep your WH slosh tube carburetors complete and ready to run.
From rebuild parts and fittings to jets, gaskets, linkage components, slosh tube parts, and carb service support, Buckshot Racing #77 is committed to keeping these proven Mercury WH carburetors alive, tuned, and race-ready.