Mercury Water Pump Repair Kit – Fits Mercury/Mariner 25/30 HP Outboards
Mercury Water Pump Repair Kit – Fits Mercury/Mariner 25/30 HP Outboards 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
Product Details
This Mercury Water Pump Repair Kit provides all necessary components to restore the cooling system on Mercury and Mariner 25 HP and 30 HP outboard engines. It is designed for a broad range of 2-stroke and 4-stroke models manufactured between 1994 and 2023, ensuring reliable performance for engine maintenance and overhauls.
The kit serves as a direct replacement for Mercury part numbers 47-89984Q5 and 47-89984T5, Sierra 18-3214, and GLM 12070, offering an exact-fit solution for a straightforward installation.
- Engineered for direct OEM replacement fit and function.
- Fully compatible with both saltwater and freshwater marine environments.
- Includes the essential impeller, housing, and gaskets for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 47-89984Q5 |
| Mercury | 47-89984T5 |
| Sierra | 18-3214 |
| GLM | 12070 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit fits a wide variety of Mercury and Mariner outboards. Please check your specific model and year against the compatibility list to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 25 | 25 | 2-Stroke | 1994–2008 | 47-89984Q5 | |
| Mercury | 30 | 30 | 2-Stroke | 1994–2008 | 47-89984Q5 | |
| Mercury | 25/30 EFI | 25/30 | 4-Stroke | 2005–2023 | 47-89984Q5, 47-89984T5 | |
| Mercury | 25/30 FourStroke | 25/30 | 4-Stroke | 2005–2023 | 47-89984Q5, 47-89984T5 | |
| Mercury | 25 SeaPro | 25 | 2-Stroke | 1994–2008 | 47-89984Q5 | Commercial models |
| Mercury | 25 ProKicker | 25 | 4-Stroke | 2005–2023 | 47-89984Q5, 47-89984T5 | |
| Mercury | 25/30M | 25/30 | 2-Stroke | 1994–2008 | 47-89984Q5 | Manual models |
| Mercury | 30E, 30EH | 30 | 2-Stroke | 1994–2008 | 47-89984Q5 | Electric start models |
| Mariner | 25/30 | 25/30 | 2-Stroke | 1994–2008 | 47-89984Q5 | |
| Mariner | 25/30 FourStroke | 25/30 | 4-Stroke | 2005–2023 | 47-89984Q5, 47-89984T5 |
Technical Specs
- Product Type
- Water Pump Repair Kit
- Installation
- Direct OEM replacement
- Product Dimensions
- 33.0 cm L x 23.0 cm W x 17.5 cm H
- Compatibility
- Compatible with saltwater and freshwater use
- Warranty
- Manufacturer standard warranty
What’s in the Box
- 1 x Water Pump Repair Kit (47-89984Q5/47-89984T5)
- 1 x Water Pump Impeller
- 1 x Water Pump Housing
- 1 x Gasket Set
- 1 x Face Plate
- 1 x Fastener/Hardware Set
- 1 x Mounting Base
Installation Notes
- Disconnect the negative battery cable and remove the propeller for safety.
- Drain the gearcase lubricant into a suitable container.
- Remove the lower unit mounting bolts and carefully separate the lower unit from the engine's upper section.
- Unbolt and remove the old water pump housing, impeller, and gaskets. Note the orientation of all parts.
- Thoroughly clean the mating surfaces on the gearcase, removing all traces of old gasket material.
- Install the new base gasket, wear plate, and impeller key from the kit.
- Slide the new impeller onto the driveshaft, rotating it in the direction of engine operation.
- Apply a thin layer of marine grease to the inside of the new pump housing and install it over the impeller.
- Reinstall the lower unit, ensuring the shift shaft and water tube align correctly. Torque bolts to manufacturer specifications.
- Refill the gearcase with the correct type and amount of new lubricant before starting the engine.
Troubleshooting & FAQ
How do I know if this kit fits my engine?
This kit is designed for Mercury/Mariner 25 HP and 30 HP outboards from 1994–2023. The best way to ensure a match is to compare your existing part numbers to the ones listed in our Part Number Matrix (Mercury 47-89984Q5, 47-89984T5, etc.) and verify your model in the Engine Compatibility table.
What are the signs of a failing water pump impeller?
Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "telltale" outlet, and in severe cases, an engine overheat alarm. The impeller is a rubber component that wears out and becomes brittle over time.
How often should the water pump be serviced?
As a critical maintenance item, the water pump and impeller should be inspected annually and replaced every 300 operating hours or every three years, whichever comes first. This interval can be shorter if the engine is operated in sandy, silty, or saltwater conditions.
Is any special grease needed for installation?
Yes, it's highly recommended to apply a light coat of marine-grade grease or a soap-and-water solution to the inside of the new pump housing and on the impeller vanes. This lubricates the impeller on its first dry start before water circulates.
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.
