Tecnoseal Mercury / Mercruiser Alpha One Generation I Anode Engine Kit

Tecnoseal Alpha One Generation I sterndrive anode kits are complete four-piece replacement sets for compatible Mercury/MerCruiser MR and Alpha One Gen I drives. Zinc, aluminium and magnesium options are available, with every kit containing matched alloy-specific anodes for the gimbal housing or driveshaft plate, trim tab and two gimbal nuts. Fixing hardware is included.

Which Drive Is This Kit For?

Confirmed serial-number application: Mercury/MerCruiser MR and Alpha One Generation I sterndrives with serial numbers from 6225577 to 0D469828.

Mercury currently describes this serial range as 1984–1990 on some product pages and 1984–1991 on others. The serial number and physical anode arrangement should therefore be treated as the primary compatibility checks.

This kit is not suitable for Alpha One Generation II drives. Gen II drives normally begin at serial number 0D469829 and use the different Tecnoseal KITALPHAONE configuration.

What Is Included?

Every alloy option contains four sacrificial-anode pieces manufactured from the selected material:

• 1 × gimbal-housing/driveshaft-plate anode: 00806BIS zinc, 00806BISAL aluminium or 00806BISMG magnesium
• 1 × trim-tab fin anode: 00800 zinc, 00800AL aluminium or 00800MG magnesium
• 2 × gimbal nut anodes: 00807 zinc, 00807AL aluminium or 00807MG magnesium
• Fixing hardware: Included with every kit

All components supplied in a selected kit are manufactured from the same alloy. The kit does not contain a mixture of zinc, aluminium and magnesium anodes.

Key Features

• Brand: Tecnoseal
• Product category: Sterndrive sacrificial-anode kit
• Manufacturer kit numbers: KITALPHAONEGEN1, KITALPHAONEGEN1AL and KITALPHAONEGEN1MG
• Drive compatibility: Mercury/MerCruiser MR and Alpha One Generation I
• Confirmed serial range: 6225577–0D469828
• Model-year guide: Commonly catalogued as 1984–1990; some current Mercury listings state 1984–1991 for the same serial range
• Number of sacrificial-anode pieces: Four
• Available alloys: Zinc, aluminium and magnesium
• Fixing hardware: Included
• Application: Multi-position cathodic protection for the sterndrive assembly
• Boat type: Motorboats fitted with a compatible MR or Alpha One Gen I sterndrive
• Manufacture: Made in Italy by Tecnoseal

Which Anode Alloy Should I Choose?

• Zinc: A conventional selection for salt-water operation where zinc is specified by the vessel or drive manufacturer.
• Aluminium: A lower-mass option suitable for fresh or salt water according to Mercury's current MR and Alpha One aluminium-kit guidance. It is also commonly selected for brackish-water use.
• Magnesium: Intended for fresh-water operation only. Magnesium is normally unsuitable for prolonged salt-water use because it can be consumed too quickly.

Use the alloy specified by Mercury, the vessel manufacturer or the existing cathodic-protection design. Keep all replacement anodes on the sterndrive consistent unless a qualified marine-corrosion specialist specifies otherwise.

Water salinity, connected metals, shore-power arrangements, bonding condition and stray-current activity can affect the correct alloy selection.

How Do I Confirm Compatibility?

Before ordering, check:

• The drive is a Mercury/MerCruiser MR or Alpha One Generation I, not Alpha One Gen II.
• The serial number is within 6225577–0D469828.
• The existing installation uses one trim-tab anode, one gimbal-housing or driveshaft-plate anode and two gimbal nut anodes.
• The selected alloy is appropriate for the operating water and existing cathodic-protection system.
• The drive has not been modified with non-standard housings, trim components or anode positions.

Do not select the kit solely from the boat manufacturer, engine horsepower, approximate model year or the words “Alpha One”.

Installation and Maintenance

Remove the existing anodes and clean each anode seat, fixing point and required electrical-contact surface. Paint, corrosion deposits, grease and sealant can interrupt the direct metal-to-metal contact required for sacrificial protection.

Fit all four anode pieces using the supplied hardware and the Mercury/MerCruiser installation and tightening procedure. Confirm that each anode is secure and electrically connected to the drive component it protects.

Do not paint the sacrificial anodes or their contact surfaces. Inspect them during scheduled servicing and replace them when substantially consumed, damaged, loose or heavily pitted. Unusually rapid, uneven or localised consumption can indicate incorrect alloy selection, poor electrical continuity, bonding faults or stray-current activity.

Alloy Standards and Manufacture

Tecnoseal manufactures zinc, aluminium and magnesium sacrificial anodes at its foundry in Grosseto, Tuscany. Alloy composition is checked using spectrometric measurements against the applicable material specification:

• Zinc alloy: US Mil Spec A-18001K
• Aluminium alloy: US Mil Spec A24779 SH
• Magnesium alloy: US Mil Spec A21412 SH

Tecnoseal states that its catalogue anodes are manufactured in Italy and checked for compliance with the applicable alloy specifications.

Frequently Asked Questions

• Is fixing hardware included? Yes. Tecnoseal lists fixing hardware as included with all three alloy variants.
• How many anodes are included? Four pieces: one gimbal-housing or driveshaft-plate anode, one trim-tab anode and two gimbal nut anodes.
• Will this fit an Alpha One Generation II drive? No. Alpha One Gen II uses a different six-piece kit configuration.
• Why do some listings say 1984–1990 and others say 1984–1991? Mercury currently uses both date ranges for products covering serial 6225577–0D469828. Check the serial number rather than relying on model year alone.
• Are all components made from the selected alloy? Yes. Selecting zinc, aluminium or magnesium provides a complete matched kit in that alloy.
• Can different anode alloys be mixed on the drive? Use a consistent alloy strategy unless the drive manufacturer or a qualified marine-corrosion specialist specifies otherwise.
• Does this kit include every anode required for the boat? No. It covers the stated sterndrive configuration. Separate hull, shaft, propeller or other equipment anodes may still be required.
• Can the new anodes be painted? No. Keep all sacrificial surfaces and required electrical-contact faces free from paint, grease and sealant.
• Why do the kit weights differ? Zinc, aluminium and magnesium have different densities, so equivalent anode shapes have different weights.

Specifications