Water Pump Impeller – Fits Mercury Mariner 3.5-9.8HP (Replaces Mercury 47-89980)
Water Pump Impeller – Fits Mercury Mariner 3.5-9.8HP (Replaces Mercury 47-89980) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Impeller – Fits Mercury Mariner 3.5-9.8HP (Replaces Merc...
Product Details
This Water Pump Impeller – Fits Mercury Mariner 3.5-9.8HP (Replaces Mercury 47-89980) is an essential replacement part for maintaining your engine’s cooling system. It is designed for a range of Mercury and Mariner outboards from 3.5HP to 9.8HP, including both 2-stroke and 4-stroke models manufactured between 1979 and 1985.
It serves as a direct interchange for multiple aftermarket part numbers, including SouthMarine MC-IM-47-89980, ITACO 47-89980, Sierra 18-3054, Mallory 9-45304, and CEF 500314, ensuring broad compatibility.
- Features a durable brass hub for reliable performance.
- Engineered with six blades for efficient water circulation.
- Installs within the engine's lower unit water pump housing.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury (OEM) | 47-89980 |
| SouthMarine | MC-IM-47-89980 |
| ITACO | 47-89980 |
| Sierra | 18-3054 |
| Mallory | 9-45304 |
| CEF | 500314 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury and Mariner models, it's crucial to check your engine's serial number against the ranges provided to ensure a perfect fit.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 3.5HP | 3.5 | 2- & 4-Stroke | 1979–1985 | 47-89980 | Serial 6202173 & up |
| Mercury | 3.6HP | 3.6 | 2- & 4-Stroke | 1979–1985 | 47-89980 | Serial 5404657 & up |
| Mercury | 4HP | 4 | 2- & 4-Stroke | 1979–1985 | 47-89980 | Serial 5589202 thru 5595531 (2 Cyl. product of USA); 5595532 to A809600 (1 Cyl. product of USA) |
| Mercury | 4.5HP | 4.5 | 2- & 4-Stroke | 1979–1985 | 47-89980 | Serial 5595532 & up (1 Cyl.) |
| Mercury | 7.5HP | 7.5 | 2- & 4-Stroke | 1979–1985 | 47-89980 | Serial 5206550 & up |
| Mercury | 9.8HP | 9.8 | 2- & 4-Stroke | 1979–1985 | 47-89980 | Serial 5206550 & up |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Engine Mount/Transom Mount
- Fuel Type
- Gasoline
- Dimensions
- Height: 4.0 in; Width: 5.13 in; Length: 0.63 in
- Weight
- 11 g (0.024 lb)
- Blades
- 6
- Hub Material
- Brass
What’s in the Box
- 1 x Water Pump Impeller (Replaces 47-89980 / 47-68988 / 18-3054)
Installation Notes
- Disconnect the spark plug leads and the battery for safety.
- Shift the outboard into neutral and remove the lower unit (gearcase) by unbolting it from the engine leg.
- Locate and unbolt the water pump housing to expose the old impeller.
- Inspect the housing, wear plate, and seals for grooves, cracks, or warping. Replace if damaged.
- Remove the old impeller, noting the rotational direction of the blades. Clean any debris from the housing.
- Apply a light coat of marine grease to the new impeller and inner housing.
- Install the new impeller by aligning it with the key on the driveshaft and turning the shaft clockwise to seat the blades.
- Reassemble the pump housing, ensuring gaskets are aligned, and tighten bolts to the manufacturer's torque specs.
- Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are properly aligned.
- Reconnect the battery and spark plugs. Test the engine using a water source (flushing muffs or in water) to confirm a strong tell-tale stream.
Troubleshooting & FAQ
How do I know if this impeller fits my specific engine serial number?
Our compatibility table lists the correct serial number ranges for each engine model. Always verify your engine's serial number against this data before ordering to guarantee a match.
What are the signs of a failing water pump impeller?
Common signs include the engine overheating at idle or low speeds, and a weak or non-existent water stream from the "tell-tale" outlet. Reduced engine performance can also be an indicator.
How often should I replace my impeller?
For preventative maintenance, it is recommended to replace the impeller every 1 to 2 years, or every 100-200 hours of operation, especially if used in saltwater or silty/sandy conditions.
Is this impeller for 2-stroke or 4-stroke engines?
This part is listed as compatible with both 2-stroke and 4-stroke Mercury/Mariner models manufactured between 1979–1985. Check the compatibility table for your specific model and HP.
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
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
