Water Pump Impeller and Plate Kit for Mercury Mariner 2-Stroke 15–25 HP Outboards
Water Pump Impeller and Plate Kit for Mercury Mariner 2-Stroke 15–25 HP Outboards is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Water Pump Impeller and Plate Kit for Mercury Mariner 2-Stroke 15–2...
Water Pump Impeller and Plate Kit for Mercury Mariner 2-Stroke 15–25 HP Outboards is backordered and will ship as soon as it is back in stock.
Product Details
This water pump impeller and plate kit is intended for selected Mercury and Mariner 2-stroke outboard engines in the 15–25 HP range. The kit is supplied for water-pump service and includes the impeller and pump plate needed for the applicable repair.
Replacing a worn impeller helps restore water-pump circulation and supports proper engine cooling. Always compare the engine model, stroke, serial number, and original part before installation.
- Application: Mercury and Mariner 2-stroke outboard water-pump service.
- Kit contents: Water pump impeller and plate.
- Installation method: Direct replacement for the applicable original water-pump components.
- Housing: Water-pump housing is not included.
- Brand status: Aftermarket replacement; Mercury and Mariner references are provided for identification.
Part Number Matrix
The following manufacturer references are listed for identifying the applicable impeller and water-pump service application. Part-number appearance does not replace model and serial-number verification.
| Reference Brand | Reference Number | Reference Type |
|---|---|---|
| Mercury / Mariner | 47-85089-1 | Listed impeller reference |
| Mercury / Mariner | 47-85089-3 | Listed impeller reference |
| Mercury / Mariner | 47-85089-10 | Listed impeller reference |
| Mercury / Mariner | 47-85089-20 | Listed impeller reference |
| Mercury / Mariner | 47-8M0027792 | Listed impeller reference |
| GLM Marine | 12107 | Aftermarket reference |
| Sierra Marine | 18-3215 | Aftermarket reference |
Engine & Model Compatibility
This kit is listed for the following Mercury and Mariner 2-stroke applications. The model, horsepower, stroke, and serial conditions must be considered together.
| Brand | Model or Application | Rated HP | Stroke | Serial Condition |
|---|---|---|---|---|
| Mercury / Mariner | 15 XD / BigFoot | 15 HP | 2-Stroke | Verify exact model and serial number |
| Mercury / Mariner | 18 / 18XD | 18 HP | 2-Stroke | Verify exact model and serial number |
| Mercury / Mariner | 20 / 20XD | 20 HP | 2-Stroke | Verify exact model and serial number |
| Mercury / Mariner | 25 Sea Pro, Marathon, and Super 15 | 25 HP | 2-Stroke | Verify exact model and serial number |
| Mercury / Mariner | 25 HP 3-cylinder | 25 HP | 2-Stroke | S/N E268781 and later |
Important: The available company fitment records identify these 2-stroke applications. They do not establish compatibility with the separate 4-stroke 323 cc BigFoot applications or with Force outboards, so those applications are not included in this listing.
Technical Specs
- Product Type
- Water pump impeller and plate kit
- Application
- Selected Mercury and Mariner 2-stroke outboards
- Rated Engine Range
- 15–25 HP, subject to the listed model and serial conditions
- Housing
- Not included
- Product Status
- Aftermarket replacement
What’s in the Box
- 1 x Water pump impeller
- 1 x Water pump plate
The water-pump housing and any components not specifically listed above are not included.
Installation Notes
- Confirm the engine model, horsepower, 2-stroke configuration, serial number, and original impeller reference before beginning work.
- Disconnect the battery where applicable and follow the outboard manufacturer’s safety procedures.
- Remove the lower unit according to the service instructions for your exact engine.
- Remove the water-pump housing and retain the fasteners and components that are to be reused.
- Remove the old impeller and pump plate, then inspect the housing, drive key, mating surfaces, and related hardware for wear or damage.
- Clean the mating surfaces before installing the replacement plate and impeller.
- Install the impeller in the correct direction and position for the engine. Use the manufacturer’s specified lubricant and installation method where required.
- Reinstall the water-pump housing and tighten fasteners to the manufacturer’s specified torque.
- Reinstall the lower unit and reconnect any removed linkages, wiring, and hardware.
- Run the engine only with an appropriate water supply or while the boat is in the water. Confirm a steady tell-tale stream and check for leaks or overheating.
Because water-pump designs and torque specifications vary by model, consult the service manual for the exact engine before installation.
Troubleshooting & FAQ
How do I confirm this kit fits my engine?
Verify that your outboard is one of the listed Mercury or Mariner 2-stroke applications, then match the horsepower, model designation, serial condition, and original impeller reference. Do not rely on horsepower alone.
Does this kit fit Force outboards?
Force compatibility is not established in the applicable company fitment record for this product, so Force outboards are not included in the confirmed fitment list.
Does this kit fit 4-stroke BigFoot engines?
The primary company fitment record for this listing specifies 2-stroke applications. The separate 4-stroke BigFoot references found in related records are not combined with this 2-stroke fitment list.
What are the signs of a failing water-pump impeller?
Common symptoms include a weak or intermittent tell-tale stream, an overheating warning, steam, or an engine that runs hotter than normal. Stop operation if the engine overheats and inspect the cooling system.
Is the water-pump housing included?
No. This listing includes the impeller and pump plate. The water-pump housing is not included.
Can I replace only the impeller?
The impeller is a serviceable component, but this product is supplied as an impeller-and-plate kit. Inspect the housing, plate, key, and related components during service and replace worn parts as required by the engine manufacturer’s service procedure.
Is this an OEM component?
No. This is an aftermarket replacement. Mercury and Mariner numbers are provided as reference numbers for identification and fitment checking.
Safety & Important Info
- Verify the exact engine model, horsepower, stroke, serial number, and original part before ordering.
- Do not operate an outboard without an adequate water supply.
- Stop immediately if the engine overheats or the tell-tale stream is absent or weak.
- Use the manufacturer’s service manual for torque values, lower-unit procedures, and inspection requirements.
- Professional installation is recommended if you are not experienced with outboard lower-unit and water-pump service.
About Sea Sierra
- Marine Replacement Parts — Practical replacement components for routine outboard maintenance and repair.
- Fitment-Focused Listings — Model, horsepower, stroke, and serial conditions are provided to support careful part selection.
- Worldwide Fulfillment — Shipping options and delivery estimates are shown at checkout based on destination and availability.
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.
