Upper Water Pump Repair Kit – Fits MerCruiser Alpha One Gen II (Replaces 817275Q05)

$52.00

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Upper Water Pump Repair Kit – Fits MerCruiser Alpha One Gen II (Replaces 817275Q05) is backordered and will ship as soon as it is back in stock.

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You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This Upper Water Pump Repair Kit is designed for MerCruiser Alpha One Generation II sterndrive units manufactured from 1991 and newer (serial numbers 0D469859 and up). It provides all necessary components for a complete upper pump housing replacement.

It serves as a direct interchange for Mercury part numbers 817275Q05 and 817275K05, as well as aftermarket equivalents from Sierra (18-3147) and GLM (12043).

Complete 11-piece kit for a full upper unit rebuild.
Features a durable stainless steel housing for longevity.
Engineered for direct-fit installation on the sterndrive.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket brands.

Brand	Part Number
Mercury	817275Q05
Mercury	817275K05
Sierra	18-3147
GLM	12043

Engine & Model Compatibility

Confirm your engine model and serial number range in the table below to ensure correct fitment.

For MerCruiser Sterndrives: This kit is specifically for Alpha One Gen II drives. It is not compatible with Gen I or other models. Please verify your drive's serial number before ordering.

For Mercury Outboards: While cross-referenced, please note that complete year ranges for compatible outboard models are not available. We recommend verifying your specific model and serial number against the OEM part number (817275Q05) independently.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
MerCruiser	Alpha One Gen II	N/A	N/A	1991 and newer	817275Q05	Serial numbers 0D469859–0F679999
MerCruiser	Alpha One Gen II	N/A	N/A	1991 and newer	817275Q05	Serial numbers 0F680000–0K999999
MerCruiser	Alpha One Gen II	N/A	N/A	1998 and newer	817275Q05	Serial numbers 0L100040 and up

Technical Specs

Product Type: Upper Water Pump Repair Kit
Installation: Complete unit replacement
Connection: Direct mount to stern drive
Housing Material: Stainless steel
Housing Color: Silver/metallic
Fitting Type: Direct fit, stainless steel guide fittings
Kit Contents: 11-piece complete kit
Warranty: Varies by manufacturer

What’s in the Box

Each package contains a complete 11-piece kit, including:

1 x Upper Housing
1 x Impeller
1 x Impeller Key
1 x Water Pump Base Gasket
1 x O-ring
Water Guide Fittings
Additional Gaskets and Plates
1 x Face Seal with Installation Tool (Note: may vary by kit)

Installation Notes

Professional installation is highly recommended. The following are general, non-exhaustive steps for replacing the water pump assembly on a typical sterndrive:

Ensure the engine is off and disconnect the battery.
Shift the drive into forward gear to aid in reassembly.
Remove the complete sterndrive unit from the transom assembly.
Place the drive on a suitable workstation and separate the upper and lower housing units.
Unscrew the bolts securing the old water pump housing and remove it.
Carefully clean all mating surfaces, removing any old gasket material or debris.
Assemble the new impeller, key, gaskets, and plates per the manufacturer's diagram. Use a light lubricant on the impeller.
Install the new water pump assembly and torque bolts to the specified value.
Rejoin the upper and lower drive units, ensuring the shift shaft and water tube align correctly.
Reinstall the sterndrive onto the transom and secure it.
Reconnect the battery, supply cooling water to the drive, and start the engine. Check for proper water flow and leaks.

Troubleshooting & FAQ

How do I confirm this kit fits my MerCruiser drive?

This kit is specifically for MerCruiser Alpha One Gen II models from 1991 onwards. Your drive's serial number must be 0D469859 or higher. It will not fit Alpha One Gen I or other MerCruiser models.

What are the signs of a failing water pump?

Common symptoms include the engine overheating at idle or low speeds, a low reading on the water pressure gauge, or a visibly dry, cracked, or brittle impeller during an inspection.

How often should the water pump be serviced?

For preventative maintenance, it is recommended to replace the impeller every one to two seasons or every 100-200 hours of use. Service intervals should be shorter for boats operated in saltwater or sandy/silty conditions.

Is this a complete kit for the job?

Yes, this is a complete upper water pump repair kit containing the housing, impeller, gaskets, plates, o-rings, and other hardware required for a standard rebuild.

Will this kit fit a Mercury Vazer drive?

While the OEM part number is cross-referenced for Vazer drives, we cannot guarantee fitment without specific model year and serial number information. Please verify compatibility independently before purchasing.

Are there any differences between this kit and the OEM version?

This is an aftermarket part designed to meet or exceed OEM specifications for fit and function. It offers a cost-effective alternative to the original manufacturer's part without sacrificing quality. The primary housing is made from durable stainless steel.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

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