The Buckshot Racing #77 Mercury Lower Unit Anode Kit is a complete corrosion-protection package for compatible Mercury and Mariner 2.0L, 2.4L, 2.5L, 3.0 Liter V6 two-stroke lower units, covering many applications.
Sacrificial anodes help protect the aluminum gearcase from galvanic corrosion. Because the anode material is more electrochemically active than the surrounding aluminum, it is designed to corrode first, helping protect expensive lower-unit, bearing-carrier and trim components.
Anodes are a normal service item and should be inspected regularly.
How Mercury Sacrificial Anodes Work
A Mercury lower unit combines aluminum castings, stainless hardware and other metals in a wet environment. When dissimilar metals are electrically connected in water, galvanic current can develop.
The sacrificial anodes provide a more reactive material for that process to attack. For them to work properly, the anodes must have good electrical contact with the gearcase and should not be painted or insulated from the mounting surface.
When Should Anodes Be Replaced?
A good service rule is to replace an anode when approximately 50% of the original material has been consumed.
Do not wait until the anode is almost gone. Boats used in saltwater, brackish water or marinas with shore power should be inspected more frequently because corrosion can progress faster.
If an anode shows almost no deterioration after extended use, inspect for poor electrical contact, painted surfaces, heavy oxidation or an incorrect anode type.
Mercury 2.0L, 2.4L, 2.5L & 3.0L Applications
This Buckshot Racing #77 kit fits many 1976-2005 Mercury V6 lower units used with 2.0L, 2.4L, 2.5L and 3.0L two-stroke outboards.
Typical applications include many 135, 150, 175, 200 and 225 HP Mercury and Mariner engines, including numerous Black Max, XR2, XR4, XR6, XRi, EFI, Pro Max and Mercury Racing configurations using the compatible gearcase and anode arrangement.
Because Mercury used several lower-unit designs over this production period, verify the existing anode locations and gearcase configuration before ordering.
Complete Anode Kit
Each Buckshot Racing #77 Mercury Lower Unit Anode Kit includes:
- 1 Trim Tab Anode
- 1 Stainless Trim Tab Bolt
- 1 Stainless Trim Tab Washer
- 2 Rectangular Sacrificial Anodes
- 1 M6 x 40 Stainless Upper Anode Screw
- 1 M6 Stainless Nylon Locknut
The included stainless hardware replaces old, corroded or damaged mounting hardware during routine lower-unit service.
Trim Tab & Rectangular Anodes
The trim-tab anode mounts above the propeller on compatible Mercury gearcases. In addition to providing sacrificial corrosion protection, its position may also help compensate for steering torque on certain installations.
The two rectangular anodes provide additional protection at compatible gearcase or transom-area mounting locations. If one anode is heavily deteriorated, inspect the entire anode system rather than replacing only the most visible piece.
The system works best when all specified anodes are present and in good condition.
Buckshot Racing #77 Installation Tech Tip
- Before installing new anodes, clean the mounting surfaces enough to provide direct metal-to-metal contact. Do not paint the anodes or coat the contact areas with insulating material.
- Inspect the surrounding aluminum for pitting, corrosion and damaged mounting threads. Install the new hardware securely using the correct Mercury service procedure for the specific lower unit.
The Buckshot Racing #77 Mercury Lower Unit Anode Kit is an inexpensive way to help protect costly gearcase components from galvanic corrosion. Replacing worn anodes before they are fully consumed can significantly reduce corrosion damage and help extend the service life of compatible Mercury 2.0L, 2.4L, 2.5L, and 3.0L V6 lower units.
Contact Mike Hill with technical questions at 714-697-1716