Water Pump Impeller Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces 46-92970A5, 47-89980Q1)
Water Pump Impeller Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces 46-92970A5, 47-89980Q1) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Impeller Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces...
Water Pump Impeller Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces 46-92970A5, 47-89980Q1) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Kit is a direct-fit replacement for Mercury and Mariner 2-stroke outboard engines ranging from 3.9 to 9.8 HP, manufactured between 1975 and 1986. It is specifically designed for models with a 0.438-inch driveshaft diameter, ensuring reliable cooling system performance.
It serves as a direct cross-reference for multiple OEM and aftermarket part numbers, including Mercury 46-92970A5, 47-89980T1, 47-89980Q1, Sierra 18-3446, GLM 89650, and CEF 500390.
- Direct replacement installation requires no modifications.
- Complete kit includes all necessary gaskets for a full water pump service.
- Engineered for vintage outboards with a 0.438" shaft diameter.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 46-92970A5 |
| Mercury | 47-89980T1 |
| Mercury | 47-89980Q1 |
| Sierra | 18-3446 |
| GLM | 89650 |
| CEF | 500390 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury/Mariner owners: This kit fits a specific range of vintage 2-stroke outboards from 1975–1986. Please verify your horsepower and shaft diameter (0.438") before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | Outboard | 3.9 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
| Mercury | Outboard | 4 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
| Mercury | Outboard | 4.5 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
| Mercury | Outboard | 6 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
| Mercury | Outboard | 7.5 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
| Mercury | Outboard | 9.8 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
| Force | Outboard | 3.9-9.8 | 2-Stroke | 1975–1986 | 46-92970A5 | 0.438" shaft diameter |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Direct Replacement
- Impeller Insert Size
- 0.438 inch (11.13 mm)
- Warranty
- 1 Year
- Kit Contents
- Complete kit includes impeller and all necessary gaskets for water pump service.
What’s in the Box
- Impeller
- Gaskets
- Seals
Installation Notes
- Disconnect the spark plug leads and battery for safety.
- Shift the outboard into neutral and remove the lower unit (gearcase) bolts.
- Carefully lower and remove the gearcase, disconnecting the shift shaft if necessary.
- Unbolt and remove the water pump housing cover to access the impeller.
- Remove the old impeller, gaskets, and wear plate, noting their orientation.
- Clean all mating surfaces thoroughly, removing any old gasket material or debris.
- Install the new gaskets, wear plate, and impeller. Lightly grease the impeller and housing interior.
- Turn the driveshaft clockwise while pressing down on the housing to correctly seat the impeller vanes.
- Secure the housing cover with the bolts, tightening to the manufacturer's specified torque.
- Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube align correctly.
- Once reassembled, test the engine in a suitable water source to confirm water flow from the tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this kit fits my engine?
Verify your engine is a Mercury, Mariner, or compatible Force 2-stroke model between 3.9 and 9.8 HP, manufactured from 1975 to 1986. The most critical dimension is the driveshaft diameter, which must be 0.438 inches.
What are the signs of a worn-out water pump impeller?
Common symptoms include the engine running hotter than normal, a weak or intermittent water stream from the tell-tale indicator, or visible damage like cracked, brittle, or missing vanes on the impeller itself upon inspection.
How often should I replace my impeller?
As a best practice for preventative maintenance, inspect your impeller annually and plan for replacement every 1-2 years or 100-200 hours of operation, especially if you frequently operate in saltwater or debris-heavy water.
Is everything needed for the job included?
Yes, this is a complete service kit. It includes the impeller along with all the required gaskets and seals for a standard water pump replacement.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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