Heavy Duty Sea Water Pump Impeller Kit – Fits Mercury/MerCruiser V6 & V8 (Replaces 47-8M0137219)
Heavy Duty Sea Water Pump Impeller Kit – Fits Mercury/MerCruiser V6 & V8 (Replaces 47-8M0137219) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Heavy Duty Sea Water Pump Impeller Kit – Fits Mercury/MerCruiser V6...
Heavy Duty Sea Water Pump Impeller Kit – Fits Mercury/MerCruiser V6 & V8 (Replaces 47-8M0137219) is backordered and will ship as soon as it is back in stock.
Product Details
This Heavy Duty Sea Water Pump Impeller Kit is designed for Mercury/MerCruiser V6 and V8 engines (305, 350, 496 & 502 CID) manufactured from 2000 and newer, specifically those equipped with brass sea water pumps. It is not compatible with 4.5L and 6.2L models.
It serves as a direct replacement for Mercury part numbers 47-8M0137219 and 47-8M0120891.
- Engineered as a heavy-duty upgrade, ideal for pump housings with some wear.
- Critical Note: For use with brass sea water pumps only.
- The kit includes a durable 8-blade impeller and an overmolded inner wear plate for extended service life.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 47-8M0137219 |
| Mercury | 47-8M0120891 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser engines, please verify your model is a 2000-and-newer V6 or V8 equipped with a brass sea water pump. This kit does not fit 4.5L or 6.2L engines.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 305 CID (5.0L) | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Brass sea water pumps only |
| MerCruiser | 350 CID (5.7L) | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Brass sea water pumps only |
| MerCruiser | 496 CID (8.1L) | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Brass sea water pumps only |
| MerCruiser | 502 CID (8.2L) | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Brass sea water pumps only |
| MerCruiser | 4.3L MPI | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Confirmed compatible |
| MerCruiser | 5.0L MPI | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Confirmed compatible |
| MerCruiser | 350 MAG MPI | Various | 4-Stroke | 2000 and newer | 47-8M0137219 | Confirmed compatible |
Technical Specs
- Product Type
- Sea Water Pump Impeller Kit
- Intended Use
- Heavy duty replacement for worn pump housings
- Housing Compatibility
- Brass (for use with brass sea water pumps only)
- Impeller Diameter
- 2-5/8" (66.7 mm)
- Impeller Length
- 2" (50.8 mm)
- Impeller Blades
- 8
- Key Features
- 0.030" shorter heavy duty impeller; Overmolded inner wear plate
What’s in the Box
- 1 x Formed O-Ring (8M2021987)
- 1 x 0.030 inch Shorter Heavy Duty Impeller (8M0103389)
- 1 x Overmolded Inner Wear Plate (8M0072979)
Installation Notes
- Disconnect the boat's battery and shut off the fuel supply.
- Close the raw water intake seacock.
- Loosen the hose clamps and carefully remove the inlet and outlet hoses from the pump.
- Remove the mounting bolts that secure the sea water pump to the engine.
- Remove the pump's end cover to access the old impeller. Note the orientation of the impeller blades.
- Remove the old O-ring, impeller, and wear plate. Clean any debris from the housing interior.
- Lightly lubricate the new O-ring and impeller with soap and water or a suitable marine lubricant.
- Install the new overmolded wear plate.
- Install the new impeller, bending the blades in the same direction as the old one was oriented (opposite the direction of pump rotation).
- Reinstall the end cover and tighten its screws evenly.
- Remount the pump and reconnect the hoses, tightening all clamps securely.
- Open the seacock, reconnect the battery, and start the engine, immediately checking for proper water flow and leaks.
Troubleshooting & FAQ
How do I know if this impeller kit fits my engine?
This kit is specifically for MerCruiser V6 & V8 engines (305, 350, 496, 502 CID) from 2000 and newer that use a brass sea water pump. Please check our compatibility table. It is crucial to confirm your pump is brass, as this kit will not work with plastic housings. It explicitly excludes 4.5L and 6.2L models.
What are the signs of a failing impeller?
Common symptoms include the engine overheating at idle or low speeds, a noticeably weak or absent stream of water from the exhaust outlets, and, upon inspection, visible cracks, stiffness, or missing blades on the old impeller.
When should I replace my sea water pump impeller?
For preventative maintenance, we recommend replacing your impeller every 1-2 years or every 200-300 hours of operation, whichever comes first. Always replace it immediately if you notice signs of failure or overheating.
What makes this a "heavy duty" kit?
This kit features a robust 8-blade impeller that is 0.030" shorter than standard. This design helps restore pressure and flow in pump housings that have experienced minor wear over time, providing a tighter seal and more reliable performance.
Why is it only for brass pump housings?
The materials and precise dimensions of the impeller and wear plate are engineered to mate perfectly with MerCruiser's brass sea water pump housings. Using this kit in a plastic or composite pump can lead to improper fit, accelerated wear, and potential pump failure.
Is this kit difficult to install?
Installation is a task of moderate difficulty for someone with mechanical experience. If you are not comfortable performing the work, we strongly recommend professional installation. Always refer to your engine's official service manual for detailed procedures.
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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