HZSIFU Boat Motor Trim Tab Anode 3.5" for Mercury/Mariner/Force 25-50 HP — Zinc Alloy, Direct-Fit Corrosion Protection

HZSIFU Boat Motor Trim Tab Anode (3.5") is a zinc alloy sacrificial anode designed to protect Mercury, Mariner, and Force 25–50 HP outboards from galvanic corrosion and replace OEM parts 822157T2 / 822157C2.

This trim tab anode mounts on the lower unit of compatible outboard motors to take the electrical wear that would otherwise attack valuable engine components. Built from durable zinc alloy, it offers straightforward bolt-on replacement and is suitable for both 2-stroke and 4-stroke engines common on recreational and work boats. It’s a cost-effective maintenance part that helps maintain performance by preserving prop shafts, housings, and other underwater metalwork.

How does the HZSIFU trim tab anode protect my outboard motor?

The anode acts as a sacrificial metal that corrodes first, diverting electrochemical reactions away from the engine’s structural parts. Installed at the trim tab area of the lower unit, it intercepts stray currents and reduces pitting and metal loss where it’s most likely to occur.

• Made from zinc alloy formulated for marine environments.
• Sacrificial design corrodes instead of engine components.
• Mounted on the lower unit where corrosion-prone contact happens.

Will this anode fit my Mercury, Mariner, or Force 25–50 HP outboard?

Yes — the HZSIFU trim tab anode is sized and shaped to be compatible with 25–50 HP models from Mercury, Mariner, and Force. It replaces OEM part numbers 822157T2 and 822157C2, so you’ll get a direct-fit swap without modification on most models that use those parts.

• Compatible range: 25HP to 50HP outboards.
• Direct OEM replacements: 822157T2 and 822157C2.
• Fits both 2-stroke and 4-stroke engine variants.

How difficult is installation and what tools do I need?

Installation is a simple maintenance task for anyone comfortable working on an outboard lower unit. Typically you remove the old anode, position the new HZSIFU anode, and fasten it with the same hardware; basic hand tools are all that’s required.

• Common tools: socket or wrench set and possibly a torque wrench.
• Reuse existing mounting hardware unless it’s corroded — replace if needed.
• Estimated time: 10–30 minutes depending on access and condition.

How long will the anode last and when should I replace it?

Longevity depends on water type, usage frequency, and electrochemical conditions; saltwater and heavy use accelerate consumption. Inspect the anode during routine maintenance and replace it when more than half of the original material has corroded or when it no longer makes firm contact with the hull or mount.

• Inspect annually or after extended saltwater exposure.
• Replace when more than 50% consumed or loose from mounting.
• Regular inspection reduces risk of unseen corrosion on critical parts.

Who is this for? Boaters and marine technicians who operate Mercury, Mariner, or Force outboard engines in coastal, brackish, or freshwater environments and want a direct-fit OEM replacement anode. It’s suited for owners of 25–50 HP 2-stroke and 4-stroke outboards who perform their own maintenance or need a dependable part to hand to a mechanic. The HZSIFU trim tab anode gives a practical, low-cost way to reduce underwater corrosion and extend the usable life of lower-unit components.