Skeg Guard – Fits MerCruiser Alpha One Generation II (1991–Present)
This marine-grade 316 stainless steel skeg guard is engineered to protect the lower unit skeg on MerCruiser Alpha One Generation II stern drives from 1991 to the present. It features a drain hole to prevent water collection and a reinforced lower wear tab for added durability against underwater impacts.
This part serves as a direct replacement for MerCruiser 27031, SupremeMarine 1901, Quickmarine 27031, Sevencow 27031-TP1, and Yoursme 27031.
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Installation Method: Simple bolt-on installation with included hardware and drill bit.
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Material: Constructed from polished, marine-grade 316 stainless steel for superior corrosion resistance.
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Protective Design: Features a 3mm thick lower wear tab to absorb impacts and a drain hole to prevent damage from water collection and freezing.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| MerCruiser |
27031 |
| SupremeMarine |
1901 |
| Quickmarine |
27031 |
| Sevencow |
27031-TP1 |
| Yoursme |
27031 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand |
Model |
Years |
OEM Part No. |
Notes |
| MerCruiser |
Alpha One Generation II |
1991–Present |
27031 |
Standard and counter rotation applications |
Technical Specifications
| Specification |
Value |
| Product Type |
Skeg Guard Protector |
| Installation |
Bolt-on with included hardware |
| Housing Material |
Marine-Grade 316 Stainless Steel |
| Housing Color |
Silver/Polished Stainless |
| Dimensions |
Length: ~25 cm (~9.84"), Width: ~11 cm (~4.33"), Height: ~14 cm (~5.51") |
| Weight |
~0.6 kg (~1.32 lbs) |
| Fitting Type |
Self-locking hardware |
| Thread Size |
1/4" |
| Warranty |
1 Year (varies by manufacturer) |
| Other Technical Attributes |
Mirror polished finish; 3mm lower wear tab; includes drain hole to prevent water collection and freezing |
Package Contents
- 1 x Skeg Guard (27031)
- 1 x 1/4" Drill Bit
- 2 x Nuts
- 2 x Hex Wrenches
- 4 x Screws (Self-locking Stainless Steel)
Installation Guide
Follow these steps for a secure installation:
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Prepare the Skeg: Clean your sterndrive's skeg thoroughly, removing any dirt, marine growth, or debris.
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Position the Guard: Slide the skeg guard over the skeg, ensuring it sits flush and is properly aligned.
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Mark the Holes: Using the pre-drilled holes in the guard as a template, mark the two locations to be drilled on your skeg.
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Drill the Skeg: Remove the guard. Using the included 1/4" drill bit, carefully drill through the skeg at the marked points.
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Mount the Guard: Re-position the skeg guard. Insert the self-locking screws and secure them from the other side with the nuts provided.
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Tighten Hardware: Use the two included hex wrenches to tighten the hardware securely. Do not overtighten, but ensure there is no movement or rattling.
Troubleshooting & FAQ
How do I confirm this fits my Alpha One Gen II?
This skeg guard is specifically designed for all MerCruiser Alpha One Generation II drives manufactured from 1991 to the present. You can verify the fit by visually comparing it to your skeg and cross-referencing your old part number with the OEM number 27031.
What is the difference between this and the OEM part?
Our skeg guard is engineered to meet or exceed OEM specifications using high-quality, corrosion-resistant 316 stainless steel. It offers the same level of protection and durability you would expect from an OEM part but at a more accessible price.
Is drilling required for installation?
Yes, this is a bolt-on guard that requires drilling two holes into the skeg for a secure and permanent fit. We provide a 1/4" drill bit, stainless steel self-locking hardware, and hex wrenches to facilitate the installation process.
OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.