Water Pump Impeller – Fits Mercury/Mariner 3.5-9.8HP (Replaces 47-22748)
Water Pump Impeller – Fits Mercury/Mariner 3.5-9.8HP (Replaces 47-22748) 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 3.5-9.8HP (Replaces 47-2...
Water Pump Impeller – Fits Mercury/Mariner 3.5-9.8HP (Replaces 47-22748) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Impeller – Fits Mercury/Mariner 3.5-9.8HP Outboards (Replaces 47-22748) is engineered for reliable performance in a range of Mercury and Mariner 2-stroke outboards from the 1960s to the 1980s. It serves as a direct-fit replacement, restoring cooling system efficiency to prevent engine overheating.
This impeller is a direct interchange for Mercury 47-22748, Sierra 18-3012, Mallory 9-45308, GLM 89600, SEI Marine 96-299-03C, and CEF 500309.
- Designed for direct OEM replacement fitment.
- Installs via a simple press fit onto the drive shaft.
- Constructed from durable neoprene rubber with a brass alloy hub for corrosion resistance in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury | 47-22748 |
| Sierra | 18-3012 |
| Mallory | 9-45308 |
| GLM | 89600 |
| SEI Marine | 96-299-03C |
| CEF | 500309 |
Engine & Model Compatibility
Confirm your engine model and serial number in the table below. Proper fitment is critical.
For Mercury/Mariner models, verification against the serial number (S/N) range is essential for ensuring compatibility.
| Brand | Model | Rated HP | Stroke | Serial Number Range | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury | 3.5 HP | 3.5 | 2-Stroke | S/N 358136–6202172 | 47-22748 | |
| Mercury | 3.9 HP | 3.9 | 2-Stroke | S/N 1655013–2498135 | 47-22748 | |
| Mercury | 5 HP | 5 | 2-Stroke | S/N 574128–786612 | 47-22748 | |
| Mercury | 6 HP | 6 | 2-Stroke | S/N 888005–1916138 | 47-22748 | |
| Mercury | 9.8 HP (Model 110) | 9.8 | 2-Stroke | S/N 1470349–1865778 | 47-22748 | 2-cylinder model |
| Mercury | Mark 5 | - | 2-Stroke | S/N 574128–786612 | 47-22748 | |
| Mercury | Mark 6, 6A | - | 2-Stroke | S/N 888005 & Up | 47-22748 |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct OEM replacement
- Connection
- Press fit onto shaft
- Material
- Neoprene (rubber) with brass/metal alloy hub
- Color
- Black rubber with brass/metal-colored hub
- Dimensions
- Shaft Diameter (A): 11.6mm, Overall Diameter (B): 32.0mm, Height (C): 14.4mm
- Weight
- 0.45 oz (~12.8g)
- Blades/Vanes
- 6
What’s in the Box
- 1 x Water Pump Impeller (Replaces 47-22748)
Installation Notes
- Disconnect the spark plug leads and battery to prevent accidental starting.
- Place the outboard in neutral and remove the lower unit (gearcase) by unbolting it from the engine leg.
- Locate the water pump housing on top of the lower unit and remove its cover bolts.
- Slide the old impeller off the driveshaft. Note the direction of the old vanes if they are still intact.
- Clean any debris or corrosion from the housing interior and wear plate.
- Lightly lubricate the new impeller and housing with marine grease or soapy water.
- Slide the new impeller onto the driveshaft, ensuring the keyway is aligned with the drive shaft key.
- Turn the driveshaft clockwise while pressing down on the impeller to seat the vanes correctly within the housing.
- Reinstall the water pump cover, gasket, and bolts, tightening to manufacturer torque specs.
- Reattach the lower unit to the engine and test the water pump function on a flush attachment before launching.
Troubleshooting & FAQ
How do I confirm this impeller fits my engine?
The most reliable method is to match your engine's model and serial number to the ranges listed in the Engine Compatibility table. Do not rely on horsepower or year alone. If your old part has a number stamped on it, check it against the Part Number Matrix.
What are the signs of a failing water pump impeller?
Common symptoms include a weak or non-existent stream of water from the "telltale" outlet, engine overheating alarms, and reduced engine performance. Upon inspection, a worn impeller may have cracked, brittle, or missing vanes.
How often should I replace my impeller?
For preventative maintenance, it is recommended to replace the impeller every 1–2 years or every 100–200 hours of use, whichever comes first. Usage in saltwater or sandy/silty conditions may require more frequent changes.
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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