Water Pump Impeller Service Kit for Select Yamaha 2-Stroke 25–30 HP and Mercury/Mariner 20–30 HP Outboards
Water Pump Impeller Service Kit for Select Yamaha 2-Stroke 25–30 HP and Mercury/Mariner 20–30 HP Outboards is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Service Kit for Select Yamaha 2-Stroke 25–30 HP...
Water Pump Impeller Service Kit for Select Yamaha 2-Stroke 25–30 HP and Mercury/Mariner 20–30 HP Outboards is backordered and will ship as soon as it is back in stock.
Product Details
This water pump impeller service kit is intended for servicing the cooling-system water pump on select Yamaha 2-stroke 25 HP and 30 HP outboards and certain Mercury/Mariner 2-stroke 20 HP to 30 HP outboards. The kit combines the impeller and related water-pump service components listed below. Confirm the exact engine model, year, serial range, and original part number before ordering.
The listed interchange references include Yamaha part numbers 689-W0078-A6-00, 689-W0078-06-00, 689-W0078-05-00, and 689-W0078-04-00, along with Mercury/Mariner references 47-42431M, 47-84829M, 47-97793M, 47-97793T, 47-81242M, and 47-95661M. These references should be used together with your engine's model and serial information to confirm compatibility.
- Designed as a replacement water-pump service kit for specified applications.
- Includes the impeller, housing, plates, gaskets, seal, key, insert, and mounting hardware listed in the package contents.
- Inspect the existing components and compare them with the kit before installation.
Part Number Matrix
Use the following references to compare the kit with the original component numbers for your engine.
| Brand | Part Number |
|---|---|
| Yamaha | 689-W0078-A6-00 |
| Yamaha | 689-W0078-06-00 |
| Yamaha | 689-W0078-05-00 |
| Yamaha | 689-W0078-04-00 |
| Mercury/Mariner | 47-42431M / 47-84829M / 47-97793M / 47-97793T / 47-81242M / 47-95661M |
Engine & Model Compatibility
The applications below are the model references associated with this service kit. Compatibility can vary by year, serial range, shaft configuration, and lower-unit design, so verify all conditions before installation.
| Brand | Model | Rated HP | Stroke | Year / Serial Information | Reference Part Numbers |
|---|---|---|---|---|---|
| Yamaha | CV25, C25 | 25 | 2-Stroke | Verify by year and serial number | 689-W0078-A6-00; related references listed above |
| Yamaha | CV30, C30 | 30 | 2-Stroke | Verify by year and serial number | 689-W0078-A6-00; related references listed above |
| Mercury/Mariner | 20C | 20 | 2-Stroke | Verify by year and serial number | 47-42431M, 47-84829M, 47-97793M, 47-97793T, 47-81242M, 47-95661M |
| Mercury/Mariner | 25C | 25 | 2-Stroke | Verify by year and serial number | 47-42431M, 47-84829M, 47-97793M, 47-97793T, 47-81242M, 47-95661M |
| Mercury/Mariner | 28 | 28 | 2-Stroke | Verify by year and serial number | 47-42431M, 47-84829M, 47-97793M, 47-97793T, 47-81242M, 47-95661M |
| Mercury/Mariner | 30A | 30 | 2-Stroke | Verify by year and serial number | 47-42431M, 47-84829M, 47-97793M, 47-97793T, 47-81242M, 47-95661M |
Technical Specifications
- Product Type
- Water pump impeller service kit
- Application
- Select Yamaha and Mercury/Mariner 2-stroke outboards
- Installation
- Replacement water-pump service installation
- Kit Type
- Water pump service kit with impeller and related components
- Weight
- 275 g (9.7 oz)
What's in the Box
- 1 x Water Seal Damper (626-44365-01-00)
- 1 x Woodruff Key (664-44338-00-00)
- 1 x Water Pump Housing (689-44311-03-00)
- 1 x Water Pump Gasket (689-44316-A0-00)
- 1 x Cartridge Outer Plate (689-44323-03-00)
- 1 x Cartridge Gasket (689-44324-A0-00)
- 1 x Impeller (689-44352-02-00)
- 1 x Cartridge Insert (689-W4432-02-00)
- 3 x Bolts with Washers (90119-06M07-00)
Installation Notes
- Disconnect the battery and ignition-coil leads and follow the engine manufacturer's safety procedures.
- Place a drain pan under the lower unit. If required for your service procedure, remove the gearcase oil drain screw and drain the gearcase oil.
- Remove the fasteners securing the lower unit to the engine housing and carefully lower the unit.
- Remove the water-pump housing to access the impeller and related components.
- Clean the mating surfaces and remove old gasket material or sealant residue without damaging the surfaces.
- Install the replacement components in the correct order. Ensure that the impeller is installed with the vanes oriented as specified for the engine.
- Reinstall the water-pump housing and tighten the fasteners to the manufacturer's specification.
- Reattach the lower unit, refill the gearcase with the specified lubricant if it was drained, and test for proper cooling-water flow before normal operation.
Troubleshooting & FAQ
How do I confirm that this kit fits my engine?
Match your engine brand, model, horsepower, stroke, year, serial range, and original water-pump part number against the information above. The model names alone may not identify every production change. Compare the original components with the package contents before ordering or installing.
What are signs of a failing water-pump impeller?
Possible symptoms include overheating at idle or low speed, a weak or intermittent stream from the tell-tale outlet, or unusual noise from the water-pump area. During inspection, an impeller may show brittle, cracked, distorted, or missing vanes.
When should the water pump be serviced?
Inspect and replace the impeller according to the engine manufacturer's maintenance schedule and whenever the engine shows cooling-system symptoms. More frequent inspection may be appropriate for engines used in saltwater or sandy, silty, or debris-filled conditions.
Is this an OEM part?
This listing is for an aftermarket replacement service kit, not an original equipment manufacturer kit. The listed OEM and manufacturer references are provided for identification and compatibility comparison only.
What should I do if the components do not match my original parts?
Do not force installation or operate the engine with mismatched water-pump components. Recheck the engine model, year, serial number, original part number, and package contents, then contact support before installation.
Safety & Important Information
- Verify the engine model, year, serial information, and original part number before purchase.
- Compare the replacement parts with the original parts before installation.
- Do not run the engine without an adequate water supply and a correctly installed cooling-system component.
- Follow the manufacturer's service-manual procedures and torque specifications. Professional installation is recommended when appropriate.
- This is an aftermarket replacement component, not an OEM part.
About Sea Sierra
- Marine Replacement Parts — Replacement components for routine service and repair applications.
- Application-Focused Information — Use model, horsepower, stroke, year, serial, and reference-number details together when checking fitment.
- Support Before Installation — Contact support if your original part or engine information does not match the listed application details.
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