Water Pump Rebuild Kit – Fits Mercury 3.0L DFI 200-300HP Outboards (Replaces 817275A5, 817275A6)
Water Pump Rebuild Kit – Fits Mercury 3.0L DFI 200-300HP Outboards (Replaces 817275A5, 817275A6) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Worry-free returns
Worry-free returns
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).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Rebuild Kit – Fits Mercury 3.0L DFI 200-300HP Outboards ...
Product Details
This Water Pump Rebuild Kit – Fits Mercury 3.0L DFI 200-300HP Outboards (Replaces 817275A5, 817275A6) provides all necessary components for a complete service of the water pump assembly, including the housing. It is engineered for Mercury and Mariner 2-stroke outboards from 200–300HP (3.0L EFI/DFI) manufactured between 2000 and 2008, as well as specific Mercruiser Alpha One Gen 2 sterndrive applications.
This kit is a direct interchange for Mercury part numbers 817275A5 and 817275A6, Sierra 18-3147, and Mallory 9-48315.
- Engineered for direct-fit installation with no modifications needed.
- Includes a new housing, impeller, gaskets, and seals for a comprehensive rebuild.
- Designed for reliable performance in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 817275A5 |
| Mercury | 817275A6 |
| Sierra | 18-3147 |
| Mallory | 9-48315 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury/Mariner Outboards: This kit fits a range of 200–300HP 3.0L DFI/EFI 2-stroke models. Please check your specific model and year for an exact match.
For Mercury/Mercruiser Alpha One Gen 2: Compatibility is limited to sterndrive units that use this water pump design. Verifying your existing OEM part number is the best way to ensure a correct fit.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Mercury | 200HP Sport XS 3.0L | 200 | 2-Stroke | 2000–2002 | 817275A5/A6 |
| Mercury | 250HP XS | 250 | 2-Stroke | 1999–2002 | 817275A5/A6 |
| Mercury | 250HP Sport XS | 250 | 2-Stroke | 2002–2005 | 817275A5/A6 |
| Mercury | 300HP ProMax | 300 | 2-Stroke | 1999–2000 | 817275A5/A6 |
| Mercury | 300HP Optimax | 300 | 2-Stroke | 2002–2008 | 817275A5/A6 |
Technical Specs
- Product Type
- Water Pump Rebuild Kit with Housing
- Installation
- Direct replacement
- Fuel Type
- Compatible with all marine fuels
- Connection
- OEM-specified fittings
- Housing Material
- Marine-grade alloy
- Housing Color
- Silver/metallic
- Dimensions
- 292.1 × 304.8 × 393.7 mm (11.5 × 12.0 × 15.5 in)
- Weight
- 0.64 kg (1.42 lb)
- Warranty
- Manufacturer warranty
What’s in the Box
- 1 x Water Pump Housing Assembly
- 1 x Carrier Seal (18-2354)
- 1 x Impeller (18-3056)
- 1 x Impeller Plate (18-3122)
- 1 x Impeller Key (18-3293)
- 1 x O-Ring (18-7420)
- 1 x Seal Ring (18-2944)
- 1 x Face Seal and Tool (18-2599)
- 1 x Impeller Gasket (18-2564)
- 1 x Impeller Gasket (18-2566)
- 1 x Drain Screw Gasket (18-2945)
Installation Notes
- Disconnect the negative battery cable and ensure the engine is off and cool.
- Drain the gearcase lubricant from the lower unit.
- Remove the lower unit (gearcase) from the outboard midsection according to your service manual.
- Unbolt and remove the old water pump housing assembly. Note the orientation of all parts.
- Thoroughly clean the driveshaft and all mounting surfaces, removing any old gasket material or corrosion.
- Install the new gaskets, impeller plate, and impeller key onto the driveshaft.
- Slide the new impeller onto the shaft, rotating clockwise to align the key.
- Carefully install the new housing and seals over the impeller, ensuring a proper fit.
- Torque the housing bolts to the manufacturer-specified values in a crisscross pattern.
- Reinstall the lower unit, refill with fresh gear lube, and reconnect the battery.
- Start the engine at idle and confirm a steady stream of water is exiting the tell-tale port.
Troubleshooting & FAQ
How do I know if this kit fits my Alpha One Gen 2 sterndrive?
This kit fits specific Alpha One Gen 2 applications. The best way to confirm is to match your existing water pump's OEM part number (817275A5 or 817275A6) with the numbers listed in our Part Number Matrix.
What are the signs of a failing water pump impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or inconsistent water stream from the "tell-tale" cooling port, and a melted, brittle, or cracked impeller upon physical inspection.
How often should I replace my water pump components?
For preventative maintenance, we recommend inspecting the impeller annually and replacing the full kit every 1-2 years or 100-200 hours of use, whichever comes first. This interval can vary based on operating conditions (e.g., saltwater, high-debris areas).
Is the included face seal tool necessary for installation?
Yes, using the included tool (part of the 18-2599 seal kit) is highly recommended. It is specifically designed to press the face seal into place correctly without causing damage, ensuring a watertight and durable repair.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility and batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
This product is 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 for unused items in original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchase. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement part, not an OEM component.
- Professional installation is recommended for safety and optimal 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, typically arriving in 5–15 days.
- Manufacturer-Direct Value — Fair pricing on high-quality components without compromising on materials or quality control.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
