Mercury – Quicksilver 821631T3 Magnesium Anode Kit | Freshwater Use | MerCruiser R, MR, Alpha, Bravo, X, XR & XZ Drives | 821631T3

Overview

Freshwater corrosion may not be as visible as saltwater damage, but it’s just as harmful over time. The Quicksilver 821631T3 Magnesium Anode Kit is designed specifically to protect your MerCruiser sterndrive from corrosion in freshwater environments.

Made from high-purity magnesium, this OEM kit provides the strongest level of galvanic protection available for freshwater boats. It’s easy to install and fits MerCruiser R, MR, Alpha One Gen II, Bravo One, Two, Three, X, XR, and XZ drives.

Key Features

• Purpose: Prevents galvanic corrosion in freshwater environments by acting as a sacrificial anode.
• Fitment: Fits MerCruiser R, MR, Alpha One, Gen II, Bravo One–Three, X, XR, and XZ drives.
• Material: Cast from magnesium, providing better corrosion protection than aluminum or zinc in freshwater.
• Complete Kit: Includes anode, seals, and gaskets for a full installation.
• Ease of Install: Simple replacement process using basic hand tools.

Engine & Boat Compatibility

• MerCruiser R, MR, Alpha One, Gen II, Bravo One–Three, and X, XR, XZ drives
• Designed for freshwater boats such as lake cruisers, pontoons, and runabouts

Performance & Practical Benefits

The 821631T3 magnesium anode works by sacrificing itself to protect the drive and gimbal housing from corrosion caused by electric currents in freshwater. Magnesium is more active than aluminum or zinc, making it the best choice for non-salty environments.

It installs quickly and keeps your sterndrive’s metal components clean and intact, helping prevent pitting and structural damage. Regular anode replacement is a small job that saves thousands in potential repairs.

Why Buy OEM

Mercury’s OEM anodes are cast from pure magnesium alloys that provide consistent protection and even wear. Generic anodes may use impure or mixed metals that corrode unevenly or fail to activate properly in freshwater.

A genuine Quicksilver magnesium anode ensures precise fit, correct alloy composition, and reliable protection exactly as Mercury intended.

FAQ

Q1: What drives fit the Quicksilver 821631T3 anode kit?
A: It fits MerCruiser R, MR, Alpha, Alpha Gen II, Bravo One–Three, and X, XR, XZ drives.

Q2: Is it for saltwater or freshwater?
A: This kit is made from magnesium, which is ideal for freshwater protection.

Q3: What’s included in the kit?
A: The kit includes anode, seals, and gaskets for a complete installation.

Q4: How often should I replace it?
A: Check your anodes every few months and replace once they’ve worn away by roughly half.

Q5: Why OEM instead of aftermarket?
A: OEM anodes use the correct magnesium blend for optimal performance and longevity in freshwater conditions.