Water Pump Impeller for Mercury/Mariner 2-Stroke 15–30 HP and Select 4-Stroke Models
Water Pump Impeller for Mercury/Mariner 2-Stroke 15–30 HP and Select 4-Stroke Models is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
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Water Pump Impeller for Mercury/Mariner 2-Stroke 15–30 HP and Selec...
Water Pump Impeller for Mercury/Mariner 2-Stroke 15–30 HP and Select 4-Stroke Models is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller is designed for specified Mercury and Mariner outboard applications. The company fitment records identify this impeller for Mercury/Mariner 2-stroke 15–30 HP engines and the listed 4-stroke models below. It is intended as a direct replacement for the original water-pump impeller when the engine, model, stroke type, and part-number reference match.
The primary replacement references documented for this impeller are Mercury part numbers 47-85089-3, 47-85089-10, 47-85089, and 47-8508910. Sierra 18-3057 and Mallory 9-45303 are listed as aftermarket reference numbers.
- Single aftermarket water pump impeller; not a complete repair kit.
- Designed for the specified Mercury and Mariner 2-stroke and 4-stroke applications.
- High-volume, long-vane impeller configuration associated with the documented 47-85089-10 reference.
- Confirm the original impeller, engine model, stroke type, and part number before ordering.
Part Number Matrix
Use these references for identification and cross-checking. Number listings are reference information and do not replace confirmation of the complete engine application.
| Brand or Source | Reference Number | Role |
|---|---|---|
| Mercury | 47-85089-3 | OEM reference |
| Mercury | 47-85089-10 | OEM reference |
| Mercury | 47-85089 | OEM reference |
| Mercury | 47-8508910 | OEM reference |
| Sierra | 18-3057 | Aftermarket reference |
| Mallory | 9-45303 | Aftermarket reference |
Engine & Model Compatibility
The company fitment records cover the following application groups. For the 2-stroke range, verify the exact engine model and serial-number range because the supplied company data identifies the range by horsepower only.
| Brand | Stroke | Application | Model or Description | Fitment Note |
|---|---|---|---|---|
| Mercury / Mariner | 2-Stroke | 15–30 HP | Specified 2-stroke outboards | Confirm exact model and serial number. |
| Mercury / Mariner | 4-Stroke | 8 HP | Bodensee; internal application listing | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 9.9 HP | 323 cc | International or model-specific application; confirm exact model. |
| Mercury / Mariner | 4-Stroke | 13.5 HP | International | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 15 HP | Specified 4-stroke model | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 25 HP | Specified 4-stroke model | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 30 HP | Standard and 3-cylinder EFI applications | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 40 HP | Standard, 3-cylinder carbureted, Italy, and specified 3-cylinder EFI applications | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 45 HP | Bodensee | Confirm exact model. |
| Mercury / Mariner | 4-Stroke | 50 HP | Standard and Bigfoot | Confirm exact model. |
Technical Specifications
- Product Type
- Water pump impeller
- Product Configuration
- Single impeller
- Application
- Mercury / Mariner outboard cooling systems
- Vane Configuration
- High-volume, long-vane design
- Outside Diameter
- Approximately 73.0 mm (2.875 in)
- Inside Diameter
- Approximately 16.0 mm (0.625 in)
- Height
- Approximately 12.6 mm
What’s in the Box
- 1 x Water pump impeller
Important: The company record identifies this product as a single impeller, not a kit. A key, gasket, washers, O-rings, wear plate, and other water-pump service parts are not included unless separately stated in the order details.
Installation Notes
- Verify the engine model, stroke type, serial number, and original impeller reference before beginning work.
- Disconnect the battery and follow the outboard manufacturer’s service procedure for removing the lower unit.
- Remove the water-pump housing and take out the old impeller.
- Inspect the housing, wear plate, keyway, gaskets, O-rings, and related components for wear or damage. Replace service parts as required.
- Clean the housing and mating surfaces before installing the replacement impeller.
- Install the impeller using the correct key and orient the vanes in the direction specified by the engine manufacturer.
- Reassemble the water pump and lower unit using the manufacturer’s torque specifications.
- Run the engine according to the manufacturer’s testing procedure and confirm proper cooling-water flow before normal operation.
Maintenance & FAQ
How do I confirm that this impeller fits my engine?
Match your engine brand, horsepower, stroke type, exact model, and serial number to the compatibility information. Also compare the original impeller and its manufacturer reference with the documented references, including Mercury 47-85089-3 or 47-85089-10 and Sierra 18-3057.
Is this a complete water-pump kit?
No. This product is a single aftermarket water pump impeller. It does not include a key, gasket, washers, O-rings, wear plate, housing, or other repair-kit components.
What are the signs of a worn water-pump impeller?
Possible signs include weak cooling-water flow, overheating warnings, or overheating during operation. Inspect the complete cooling system because water-flow problems can have causes other than the impeller.
Should the key and gaskets be replaced at the same time?
Inspect the key, housing, wear plate, gaskets, and O-rings during service. Replace any worn, damaged, hardened, or distorted components with parts appropriate for the specific engine.
Is this an OEM component?
No. This is an aftermarket replacement impeller. The OEM and aftermarket numbers shown on this page are reference numbers for identification only.
Safety & Important Information
- Do not rely on horsepower alone. Confirm the exact model, stroke type, serial number, and original part number.
- Do not install this impeller if its dimensions, keyway, vane configuration, or reference markings differ from the original part without professional verification.
- Follow the outboard manufacturer’s service manual and torque specifications.
- Professional installation is recommended when lower-unit or water-pump service is unfamiliar.
About Sea Sierra
- Marine Replacement Parts — Practical aftermarket components for routine marine maintenance and repair.
- Application-Focused Listings — Product references and fitment information are provided to support careful part identification.
- Customer Support — Contact support with your engine model, serial number, and original part information when application assistance is needed.
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