Water Pump Impeller – Replacement for Mercury/Mariner and Force/Chrysler Outboard Applications
Water Pump Impeller – Replacement for Mercury/Mariner and Force/Chrysler Outboard Applications 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 – Replacement for Mercury/Mariner and Force/Chr...
Water Pump Impeller – Replacement for Mercury/Mariner and Force/Chrysler Outboard Applications is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller is intended for specified Mercury/Mariner and Force/Chrysler outboard water-pump applications. Fitment depends on the engine model, stroke, model year, gear-case configuration, and serial-number range, so compare your engine details and the reference numbers below before ordering.
The impeller is listed as a replacement for the Mercury Marine reference 47-850893 and related reference numbers including 47-8M0024502. The 2019 Sierra catalog identifies Sierra 18-3057 as an impeller associated with Mercury reference 47-850893; aftermarket and OEM reference numbers should be used for identification and fitment checking, not as a claim that the product is a genuine OEM component.
- Aftermarket replacement for the water-pump impeller.
- Six-blade configuration for water circulation through the cooling system.
- Neoprene rubber construction with an internal hub mount.
- Confirm the engine serial number and water-pump assembly before installation.
Part Number Matrix
The following numbers are reference identifiers associated with this impeller application. Verify the number, dimensions, and engine serial range against your original part.
| Brand or source | Reference number |
|---|---|
| Mercury Marine | 47-850893 |
| Mercury Marine | 47-85089 |
| Mercury Marine | 47-8508910 |
| Mercury Marine | 47-8508920 |
| Mercury Marine | 47-8M0024502 |
| Mercury Marine | 47-8M0027792 |
| Mercury Marine | 8M0204712 |
| Sierra | 18-3057 |
| GLM | 89640 |
| Mallory | 9-45303 |
| Mallory | 9-45303-10 |
Engine and Model Compatibility
The application list below is provided as a fitment guide. Always confirm the exact model and serial number because engines with the same horsepower rating may use different water-pump components.
| Brand | Model or application | Rated HP | Stroke | Year or serial condition | Reference | Notes |
|---|---|---|---|---|---|---|
| Mercury/Mariner | 18HP | 18 | 2-Stroke | 1984 and later; S/N 5837437 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 20HP | 20 | 2-Stroke | 1984 and later; S/N 6443973 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 25, 25XD, 25 Sea Pro | 25 | 2-Stroke | 1984 and later; S/N 5705532 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 25 three-cylinder | 25 | 2-Stroke | S/N E268781 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 30 Jet | 30 | 2-Stroke | S/N G590000 and later | 47-850893 | Jet applications require serial-number confirmation. |
| Mercury/Mariner | 30 two-cylinder | 30 | 2-Stroke | S/N G053314 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 40 two-cylinder | 40 | 2-Stroke | S/N G053314 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 40 three-cylinder | 40 | 2-Stroke | S/N G531301 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 40 standard | 40 | 4-Stroke | S/N G231123–G760299 | 47-850893 | Serial range is required for confirmation. |
| Mercury/Mariner | 40 with 2:1 ratio | 40 | 4-Stroke | S/N G760300–T408999 | 47-850893 | Serial range is required for confirmation. |
| Mercury/Mariner | 45 Bodensee | 45 | 4-Stroke | S/N G231123 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 50 three-cylinder | 50 | 2-Stroke | 1984 and later; S/N G590000 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | 50 standard | 50 | 4-Stroke | S/N G231123 and later | 47-850893 | Verify model and pump assembly. |
| Mercury/Mariner | BigFoot | 8–15 | 4-Stroke | Not specified | 47-850893 | Listed for models with the BigFoot gear case; verify before ordering. |
| Force/Chrysler | 25HP | 25 | 2-Stroke | 1996–1998; S/N E127700–E344999 | 47-850893 | Serial range is required for confirmation. |
| Force/Chrysler | 40/50HP | 40/50 | 2-Stroke | 1995–1999; S/N E093700–E369299 | 47-850893 | Serial range is required for confirmation. |
| Force/Chrysler | 75HP | 75 | 2-Stroke | 1999; S/N E345000 and later | 47-850893 | Serial range is required for confirmation. |
Technical Specifications
- Product type
- Water pump impeller
- Product construction
- Neoprene rubber impeller with internal hub mount
- Blade configuration
- 6 blades
- Color
- Black
- Dimensions
- Diameter: 73.00 mm (2.906 in); height: 12.60 mm (0.496 in); internal hub: 16.00 mm (0.629 in)
- Weight
- 41 g (0.09 lb)
- Installation type
- Direct replacement in a compatible water-pump assembly
What's in the Box
- 1 × Water pump impeller
This listing is for the impeller only. The key, gaskets, wear plate, housing, seals, and other water-pump components are not included unless specifically supplied with the compatible pump assembly.
Installation Notes
- Confirm the engine model, stroke, serial number, and original impeller dimensions before beginning work.
- Place the outboard in a secure upright position and follow the engine manufacturer's procedure for removing the lower unit.
- Remove the water-pump housing and inspect the housing, wear plate, key, gaskets, and driveshaft for wear or damage.
- Remove the old impeller and clean all mating surfaces and debris from the pump housing.
- Reuse the existing key only if it is in good condition and correctly matches the engine; replace damaged or missing components as required by the engine manufacturer.
- Install the impeller in the correct rotational orientation. A light coating of clean marine lubricant may be used where appropriate; do not use petroleum products that can damage the rubber.
- Reinstall the housing and related components using the manufacturer's torque specifications.
- Reattach the lower unit, supply cooling water, and confirm a steady tell-tale stream before operating the engine under load.
Troubleshooting and FAQ
How do I confirm fitment?
Compare the original impeller's dimensions and reference number, then confirm the engine brand, model, horsepower, stroke, gear-case configuration, and serial number against the application table. A matching horsepower rating alone is not sufficient.
What are common signs of a worn impeller?
Symptoms may include a weak or missing tell-tale stream, overheating warnings, reduced cooling-water flow, damaged blades, cracking, brittleness, or visible wear. A tell-tale stream does not by itself rule out a worn impeller.
How often should the impeller be inspected?
Inspect the impeller according to the engine manufacturer's maintenance schedule and replace it when the blades are worn, cracked, permanently set, or damaged. More frequent inspection may be appropriate in sandy, silty, or debris-filled water.
Does the impeller include a key or gasket set?
No. The box contains one water pump impeller only. A compatible key, gaskets, wear plate, housing, and other service parts must be sourced separately when required by the engine model.
Is this a genuine OEM component?
No. This is an aftermarket replacement impeller. The OEM and aftermarket numbers shown on this page are reference numbers for identification and fitment.
Safety and Important Information
- Disconnect the battery and follow the engine manufacturer's service and safety procedures before working on the outboard.
- Never run the engine without an adequate supply of cooling water.
- Do not rely on horsepower alone; verify the complete model and serial-number application.
- Stop installation if the replacement part differs in dimensions, hub design, blade count, or material from the required original part.
- Professional installation is recommended when lower-unit or water-pump service is unfamiliar.
About Sea Sierra
- Marine replacement parts — Replacement components for common outboard service applications.
- Fitment-focused information — Product references and application details are provided to support model and serial-number verification.
- Aftermarket value — A practical replacement option for servicing a compatible water-pump assembly.
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.
