Water Pump Impeller Repair Kit – Fits Mercury Marine 4–9.8 HP (Replaces 46-70941A3)
Water Pump Impeller Repair Kit – Fits Mercury Marine 4–9.8 HP (Replaces 46-70941A3) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
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Water Pump Impeller Repair Kit – Fits Mercury Marine 4–9.8 HP (Repl...
Water Pump Impeller Repair Kit – Fits Mercury Marine 4–9.8 HP (Replaces 46-70941A3) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller Repair Kit is designed for Mercury Marine 4 HP, 4.5 HP, 7.5 HP, and 9.8 HP 2-Stroke outboard motors manufactured between 1975 and 1986. It provides all the necessary components to restore your engine's cooling system to factory specifications, preventing overheating and ensuring reliable performance.
It serves as a direct interchange for Mercury 46-70941A3, Sierra 18-3446, GLM 12122, and QuickMarine 70941A3, ensuring a precise fit and function.
- Engineered for direct replacement, simplifying installation.
- Constructed with durable materials: a CR-Neoprene impeller, nylon housing, and a stainless steel (SS316) face plate for longevity.
- Kit includes a comprehensive set of seals, O-rings, and hardware for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 46-70941A3 |
| Sierra | 18-3446 |
| GLM | 12122 |
| QuickMarine | 70941A3 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit fits specific serial number ranges for Mercury outboards. Please verify your engine's serial number falls within the specified ranges to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | Outboard | 4 | 2-Stroke | 1975–1986 | 46-70941A3 | Serial 5595532 & UP (Made in USA) |
| Mercury | Outboard | 4.5 | 2-Stroke | 1975–1986 | 46-70941A3 | Serial 4107220-5595531 and 5595532 & UP |
| Mercury | Outboard | 6 | 2-Stroke | 1975–1982 | 46-70941A3 | Serial 1582403-1916138, 1916139-2193817, 2193818-2529894, 2385673-2387383 |
| Mercury | Outboard | 7.5 | 2-Stroke | 1975–1986 | 46-70941A3 | Serial 2529895-4131609, 4131610-5226934, 5206550 & UP |
| Mercury | Outboard | 9.8 (Model 110) | 2-Stroke | 1975–1986 | 46-70941A3 | Serial 1865779-2196388, 2196389-3795657, 3795658-4126459, 4126460-5206549, 5206550 & UP |
Technical Specs
- Product Type
- Water Pump Impeller Repair Kit
- Installation
- Direct replacement
- Housing Material
- Nylon
- Impeller Material
- CR-Neoprene
- Face Plate Material
- Stainless Steel (SS316)
- Impeller Insert Size
- 0.456 inches (11.6 mm) diameter
- Warranty
- 30-day returns (Amazon); 1-year (JLM Marine)
What’s in the Box
- 1 x Water Pump Impeller
- 1 x Impeller Plate (Face Plate)
- 1 x Water Pump Cover Seal
- 1 x Cover Assembly
- 1 x Housing Assembly
- 1 x Key
- 1 x Seal
- 1 x Washer
- 1 x O-ring (25-62704, 29439)
- 1 x Rubber Ring (26-30526)
- 1 x Oil Seal O-ring (26-30913)
Installation Notes
- Disconnect the battery and remove the spark plug wires for safety.
- Drain the lower unit gear lube.
- Remove the lower unit (gearcase) from the outboard motor.
- Unbolt and remove the old water pump housing assembly.
- Clean the mounting surfaces and inspect the driveshaft for wear or damage.
- Install the new key, impeller, face plate, and gaskets from the kit.
- Lightly grease the interior of the new housing and install it over the impeller, ensuring the impeller vanes are correctly oriented.
- Secure the new housing with the provided hardware and torque to manufacturer specifications.
- Re-install the lower unit, refill with fresh gear lube, and reconnect the battery and spark plugs.
- Start the engine in water and verify a steady stream from the cooling system's tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this kit fits my motor?
Verify your outboard's model, year, and especially its serial number against the ranges listed in the Engine & Model Compatibility table. Fitment is specific to these serial number breaks.
What are common signs of a failing water pump impeller?
The most common symptoms are a weak or non-existent water stream from the tell-tale outlet, an engine overheating alarm, or a noticeable decrease in engine performance as the ECU reduces power to prevent damage.
How often should I replace the impeller?
For preventative maintenance, it is recommended to replace the impeller every 1 to 2 years, or every 100-200 hours of operation. Replacement frequency should increase if you operate in saltwater or water with high sediment content.
What is the benefit of a CR-Neoprene impeller?
CR-Neoprene is a robust, flexible synthetic rubber that offers excellent resistance to heat, saltwater, oil, and abrasion, providing greater durability and a longer service life compared to standard rubber compounds.
Why does this kit include so many O-rings and seals?
This kit is designed to be comprehensive, providing all necessary seals for various serial number ranges covered by the part number. This ensures you have the correct components on hand for a complete and reliable repair without needing to source extra parts.
Is the water pump housing included?
Yes, this is a complete repair kit that includes the nylon housing assembly, impeller, face plate, and all required gaskets, seals, and hardware for a full 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.
Payment & Security
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