Martyr CMALPHAKITZ MerCruiser Alpha I Gen II Anode Kit — Zinc | Saltwater, 1991–Present

Martyr CMALPHAKITZ — MerCruiser Alpha I Generation II Zinc Anode Kit | 1991–Present

Part Number: CMALPHAKITZ (SKU: 194-CMALPHAKITZ)
Brand: Martyr Anodes
Official Product Type: Complete Sacrificial Anode Kit — Zinc
Supersedes: No known superseded number
Replaced By: CMALPHAKITZ is the current active part number

The Martyr CMALPHAKITZ is a complete zinc sacrificial anode kit engineered specifically for MerCruiser Alpha I Generation II sterndrives from 1991 to present. This kit covers all major anode positions on the outdrive in a single purchase, ensuring full cathodic protection across the trim tab, bearing carrier, driveshaft housing, gimbal housing, and trim rams. Zinc alloy construction makes this kit the correct choice for salt water environments.

Compatible Applications

• MerCruiser Alpha I Generation II sterndrives — 1991 to present
• All engine configurations paired with the Alpha I Gen II outdrive
• Salt water use only (see aluminum and magnesium alternatives below for other water types)

Kit Contents

• 1× CM762145 — Trim Tab Anode
• 1× CM806105 — Bearing Carrier Anode
• 1× CM821629C — Driveshaft Housing Anode
• 1× CM821631 — Gimbal Housing Anode
• 2× CM806189 — Trim Ram Anodes
• Fastening hardware included

System & Location

Cathodic protection system — sterndrive outdrive. Anodes mount at five positions across the Alpha I Gen II drive unit: trim tab (lower unit), bearing carrier, driveshaft housing, gimbal housing, and trim rams. Full-kit replacement ensures no position is left unprotected during a service interval.

Anode Material Guide

• Zinc (this kit): Salt water ✓
• Aluminum: Salt water & brackish water — see Martyr CMALPHAKITA Aluminum Anode Kit
• Magnesium: Fresh water only — see Martyr CMALPHAKITM Magnesium Anode Kit

Dimensions & Weight

• Weight: Approx. 680 g / 1.5 lb (estimated — full kit)
• Individual anode dimensions vary by position; all are direct-fit replacements for Alpha I Gen II mounting points

Service Interval

Inspect at every haul-out or at least once per season. Replace any anode that has been consumed to approximately 50% of its original mass. Replacing the full kit at each service interval is the most reliable way to ensure complete protection — mixing old and new anodes can reduce overall system effectiveness. Do not allow any anode to deplete fully before replacement.

Installation Notes

• Confirm your drive is an Alpha I Generation II (1991–present) before ordering — not compatible with Alpha I Generation I or Bravo series drives
• Clean mounting surfaces before installation to ensure good metal-to-metal contact
• Do not paint over anodes — paint prevents galvanic action
• Torque fasteners to specification; loose anodes can be lost underway
• Replace the full kit together for consistent protection across all drive positions

Technical FAQ

Q: How do I know if I have an Alpha I Gen II vs Gen I?
Alpha I Generation II drives were introduced in 1991. If your MerCruiser sterndrive is a 1991 or newer Alpha I, this kit fits. Gen I drives (pre-1991) use a different anode configuration.

Q: Why zinc instead of aluminum for salt water?
Both zinc and aluminum anodes work in salt water. Aluminum is generally more electrochemically efficient and is the preferred choice for most applications. Zinc is a proven, traditional option for salt water and is the correct choice if your marina or boatyard specifies zinc.

Q: Can I replace just one anode instead of the full kit?
Yes — individual anodes are available separately. However, replacing the full kit at each service interval ensures uniform protection and avoids the risk of one depleted anode leaving a drive position unprotected.

Q: Do I need to use the included hardware?
Yes. Use the supplied fastening hardware. Stainless or dissimilar metal fasteners can interfere with the anode's galvanic function if not properly matched.

Related Parts

• Martyr CMALPHAKITA — Aluminum Anode Kit (Salt & Brackish Water)
• Martyr CMALPHAKITM — Magnesium Anode Kit (Fresh Water)
• Martyr CMT-806189A — Aluminum Horseshoe Anode, Mercury Gen II Outdrive
• Mercury Alpha One Zinc Anode CMT-821631Z
• MerCruiser Alpha One Gen II Zinc Anode Kit — Alpha1G2-Kit-ZN

Parts Desk Insights

The Alpha I Gen II is one of the most common sterndrives on the water, and full anode kit replacement is the most efficient way to service it — buying individual anodes piecemeal often costs more and takes longer. The most common issue we see is customers ordering the wrong alloy for their water type, or ordering a Gen I kit for a Gen II drive. If you're unsure which generation your drive is, check the model year: 1991 and newer is Gen II. For mixed salt and brackish water use, the aluminum kit (CMALPHAKITA) is worth considering as it offers slightly better efficiency per kilogram of anode material.