Water Pump Impeller – Fits Select Yamaha 25/30 HP and Mercury/Mariner Outboards (Replaces 47-84797M, 47-81604M)
Water Pump Impeller – Fits Select Yamaha 25/30 HP and Mercury/Mariner Outboards (Replaces 47-84797M, 47-81604M) is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller – Fits Select Yamaha 25/30 HP and Mercury/Marin...
Water Pump Impeller – Fits Select Yamaha 25/30 HP and Mercury/Mariner Outboards (Replaces 47-84797M, 47-81604M) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller is a replacement cooling-system component for select Yamaha 25 and 30 HP outboards and Mercury/Mariner applications. It is intended to restore water-pump circulation and help maintain proper engine cooling when the original impeller is worn, cracked, hardened, or damaged.
Catalog references identify this impeller as replacing Mercury/Mercury Marine part numbers 47-84797M and 47-81604M. Yamaha references associated with the broader application family include 689-W0078-A6-00; always confirm the exact model, year, serial-number range, and existing impeller dimensions before ordering.
- Replacement impeller for an outboard water pump.
- Designed for use in select gasoline-fueled marine outboards.
- Supplied as the impeller only; housing, wear plate, gaskets, O-rings, bolts, and impeller key are not included unless separately stated for your order.
- Aftermarket replacement, not an original equipment manufacturer component.
Part Number References
Use these references as search and cross-reference aids only. Part-number co-occurrence does not replace model-specific fitment verification.
| Brand or application | Reference | Relationship |
|---|---|---|
| Mercury / Mercury Marine | 47-84797M | Replacement reference for the impeller |
| Mercury / Mercury Marine | 47-81604M | Replacement reference for the impeller |
| Yamaha | 689-W0078-A6-00 | Application-family reference; verify the exact engine before purchase |
Engine Compatibility
The available catalog evidence places the referenced impeller in select Mercury/Mariner and Yamaha water-pump applications. Fitment depends on the complete engine identity, including model, horsepower, stroke, year, and serial-number conditions. Do not rely on horsepower alone.
| Brand | Application information | Important verification |
|---|---|---|
| Yamaha | Select 25 and 30 HP applications associated with the 689-W0078-A6 reference family | Confirm the exact model, year, stroke, and serial range; the reference family also contains other water-pump kit configurations. |
| Mercury / Mariner | Select applications using impeller references 47-84797M or 47-81604M | Confirm the engine model and serial-number range in the service manual or parts diagram before installation. |
Technical Specifications
- Product type
- Water pump impeller
- Part configuration
- Single impeller
- Intended use
- Outboard engine cooling-system service
- Fuel type
- Gasoline marine outboards
- Brand status
- Aftermarket replacement
What's in the Box
- 1 x Water pump impeller
Not included: water-pump housing, cartridge or insert cup, wear plate, gaskets, seals, bolts, and impeller key. Replace these additional components only when required by the engine manufacturer's service procedure or their condition.
Installation Notes
Professional installation is recommended. Use the service manual for the exact engine and follow the manufacturer's removal, inspection, lubrication, sealing, and torque procedures.
- Confirm the replacement part against the engine model, year, serial number, and removed impeller.
- Remove the lower unit and water-pump cover according to the engine service manual.
- Inspect the pump housing, wear surfaces, key, water-tube seal, and gaskets for scoring, corrosion, distortion, or damage.
- Remove all fragments of the old impeller and clean the mating surfaces.
- Install the new impeller in the correct orientation, using the specified lubricant and installation method.
- Reassemble the water pump with the correct gasket and sealing components, then torque fasteners to the manufacturer's specification.
- Reinstall the lower unit and verify correct water-tube and shift-shaft alignment.
- Run the engine only in an appropriate water source or with the correct flushing equipment, and confirm a steady cooling-water tell-tale stream.
Maintenance and Troubleshooting FAQ
What are the signs of a worn water-pump impeller?
Common signs include a weak or intermittent tell-tale stream, overheating, an overheating warning, steam, or damaged impeller fragments in the water-pump area. Stop operation and investigate promptly if cooling flow is reduced.
How often should an impeller be replaced?
Replacement intervals vary by engine manufacturer, operating hours, and water conditions. Follow the service schedule for your exact engine and inspect the impeller more frequently after sandy, silty, salty, or extended-storage operation.
Does this product include a key or gasket set?
No. This listing is for one impeller only. An impeller key, housing, wear plate, gaskets, seals, and other water-pump components are not included unless specifically identified in the order details.
How do I confirm fitment?
Match the engine manufacturer's part number and the complete engine model information. Keep horsepower, stroke, year, model designation, and serial-number range together when checking a parts diagram or service manual.
Is this an OEM part?
No. This is an aftermarket replacement impeller. Yamaha, Mercury, and Mariner names and part numbers are used only to identify intended applications and reference numbers.
Safety and Important Information
- Verify the part number, dimensions, and old-part configuration before purchase and installation.
- Do not operate an outboard without adequate cooling-water supply.
- Incorrect fitment or installation can cause overheating and severe engine damage.
- Brand names and manufacturer part numbers are used for reference purposes only; this product is not manufactured by or affiliated with those brands.
About Sea Sierra
- Marine replacement parts — We provide aftermarket components for routine marine maintenance and repair.
- Application-focused listings — Product references are presented to help customers compare their original part and engine documentation.
- Support for proper selection — Always use the engine model, year, stroke, and serial information when confirming fitment.
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