Water Pump Impeller – Fits Mercury/Mariner 3.5–9.8 HP (Replaces 47-89980, 47-68988)
Water Pump Impeller – Fits Mercury/Mariner 3.5–9.8 HP (Replaces 47-89980, 47-68988) 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.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
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Water Pump Impeller – Fits Mercury/Mariner 3.5–9.8 HP (Replaces 47-...
Water Pump Impeller – Fits Mercury/Mariner 3.5–9.8 HP (Replaces 47-89980, 47-68988) is backordered and will ship as soon as it is back in stock.
Product Details
This Water Pump Impeller is built for reliable performance in vintage Mercury and Mariner 2-stroke outboard motors from 3.5 HP to 9.8 HP, generally covering models from 1966–1986. Engineered as a direct-fit replacement, it ensures proper cooling system function by matching OEM specifications for flow and pressure.
It directly replaces OEM part numbers Mercury 47-89980 and 47-68988, and serves as an interchange for Sierra 18-3054, Mallory 9-45304, and others.
- Designed for direct OEM replacement installation.
- Constructed from durable neoprene with a brass hub.
- Manufactured in an ISO9002 certified facility for quality assurance.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury | 47-89980 / 89980 |
| Mercury | 47-68988 / 68988 |
| Sierra | 18-3054 |
| Mallory | 9-45304 |
| GLM | 89800 |
| SEI Marine | 96-260-03A |
| CEF | 500314 |
| Aftermarket | AM47-89980 |
Engine & Model Compatibility
Confirm your engine model and serial number range in the table below. Pay close attention to the drive shaft diameter requirement noted in the Installation and FAQ sections.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | - | 3.5 | 2-Stroke | 1966+ | 47-89980 | S/N 6202173 & UP |
| Mercury | - | 3.6 | 2-Stroke | 1966+ | 47-89980 | S/N 5404657 & UP, 7145388 & UP, 9252831 & UP |
| Mercury | - | 4 (1 Cyl) | 2-Stroke | 1966+ | 47-89980 | S/N 5589202 THRU 0A809600 |
| Mercury | Model 40 | 4 (2 Cyl) | 2-Stroke | 1966+ | 47-89980 | S/N 5589202 & UP |
| Mercury | Model 45 | 4.5 (1 Cyl) | 2-Stroke | 1966+ | 47-89980 | S/N 5595532 & UP, 7147238 & UP, 8068065 & UP, 9258281 & UP |
| Mercury | Merc 75 | 7.5 | 2-Stroke | 1966+ | 47-89980 | S/N 5206550 & UP, 7125388 & UP, 8057545 & UP, 9217756 & UP |
| Mercury | Merc 110 | 9.8 | 2-Stroke | 1966+ | 47-89980 | S/N 5206550 & UP, 7127388 & UP, 8057545 & UP, 9217756 & UP |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct OEM Replacement
- Housing Material
- Neoprene with Metal/Brass Hub
- Number of Blades
- 6
- Dimensions
- Inner Diameter: 11.0 mm (0.438 inch), Outer Diameter: 32.0 mm (1.26 inches), Height: 14.4 mm (0.57 inches)
- Weight
- 12.76 g (0.45 oz)
- Quality Standard
- Made to OEM specifications in ISO9002 certified factory
What’s in the Box
- 1 x Water Pump Impeller (Replaces 47-89980)
Installation Notes
- IMPORTANT: Before disassembly, confirm your engine's drive shaft diameter is 0.438 inches (11.0 mm). Mercury used multiple shaft sizes on these vintage motors, and this impeller will not fit other diameters.
- Disconnect the battery and remove the engine cover.
- Place a drain pan under the lower unit and remove the gear oil drain/fill screws to drain the lubricant.
- Remove the bolts securing the lower unit (gearcase) to the engine's midsection and carefully lower it.
- Locate and unbolt the water pump housing.
- Remove the old impeller, noting the rotational direction of the existing blades.
- Clean the housing interior and install the new impeller. Apply a small amount of marine grease to the housing and impeller.
- Reassemble the water pump housing, reattach the lower unit, and refill the gearcase with fresh oil.
Troubleshooting & FAQ
How do I know if this impeller fits my specific engine?
This is critical for vintage Mercury motors. You must physically verify your drive shaft diameter is 0.438 inches (11.0 mm). Even if your model and serial number seem to match, Mercury sometimes used different drive shafts. Do not purchase if your shaft diameter is different.
Will this impeller fit a 5 HP Mercury outboard?
No, this part will not fit 5 HP Mercury models. Those typically require part number 47-16154-3.
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 "telltale" indicator outlet on the engine.
How often should a water pump impeller be replaced?
As a preventative maintenance item, it is best practice to replace the impeller every 100-200 operating hours or at least once per year, especially if operating in saltwater or silty/sandy conditions.
Is this an OEM Quicksilver/Mercury part?
This listing is for a high-quality aftermarket replacement, not an OEM component. It is built to OEM-level specifications with comparable materials and manufactured in an ISO 9002 certified facility, with batch inspections for quality and consistency.
How fast do you ship and what does it cost?
We ship worldwide quickly, with a typical transit time of 5–15 days for most regions. Standard shipping is free, and expedited options may be available at checkout depending on your location.
What is the warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our full policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement part, not an OEM component.
- Professional installation is recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world reliability.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days, getting you back on the water faster.
- Manufacturer-Direct Value — We deliver fair pricing without compromising on materials or quality control.
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