Sea Water Pump – Fits Yanmar 2GM & 3GM Series (Replaces 128377-42500, 10-24509-01)
Sea Water Pump – Fits Yanmar 2GM & 3GM Series (Replaces 128377-42500, 10-24509-01) is backordered and will ship as soon as it is back in stock.
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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
Sea Water Pump – Fits Yanmar 2GM & 3GM Series (Replaces 128377-...
Product Details
This aftermarket Sea Water Pump – Fits Yanmar 2GM & 3GM Series is designed for Yanmar marine diesel engines, specifically fitting the 2GM20-YEU, 2GM20C-YEU, 3GM30-YEU, and 3GM30C-YEU models manufactured between 1996 and 2004. It serves as a reliable replacement for maintaining your engine's cooling system.
This pump is a direct interchange for Yanmar part numbers 128377-42500 and 128397-42500, as well as Johnson pumps 10-24509-01, 10-24509-02, 10-13337-01, and 10-13492-01.
- Mounting Type: Crankshaft Mounted
- Pump Type: Self-priming flexible neoprene impeller pump
- Housing Material: Durable bronze construction
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number |
|---|---|
| Yanmar | 128377-42500 |
| Yanmar | 128397-42500 |
| Johnson | 10-24509-01 |
| Johnson | 10-24509-02 |
| Johnson | 10-13337-01 |
| Johnson | 10-13492-01 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Note for Yanmar Owners: This pump fits European-built ("YEU") models, often identified by an "E" prefix in the serial number (e.g., E00123). Please verify your specific model before ordering.
| Brand | Model | Years | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 2GM20-YEU | 1996–2004 | 128377-42500 | European built model |
| Yanmar | 2GM20C-YEU | 1996–2004 | 128377-42500 | European built model |
| Yanmar | 3GM30-YEU | 1996–2004 | 128377-42500 | European built model |
| Yanmar | 3GM30C-YEU | 1996–2004 | 128377-42500 | European built model |
Technical Specs
- Product Type
- Sea Water (Raw Water) Engine Cooling Pump
- Installation
- Crankshaft Mounted
- Connection
- 3/8 inch hose ports (inlet and outlet)
- Housing Material
- Bronze
- Housing Color
- Bronze/Brass
- Weight
- 1.23 kg (2.7 lb)
- Fitting Type
- Hose barb
- Other Technical Attributes
- Self-priming flexible impeller pump; Neoprene impeller
What’s in the Box
- 1 x Sea Water Pump Assembly (equivalent to 128377-42500)
Installation Notes
- Engage the proper safety precautions: shut off the engine, let it cool completely, close the raw water intake valve (seacock), and disconnect the battery.
- Place absorbent pads under the pump to catch any spilled coolant or water.
- Loosen the hose clamps and carefully detach the inlet and outlet hoses from the pump.
- Remove the mounting bolts that secure the pump to the engine crankshaft bracket.
- Gently remove the old pump. Clean the mounting surface on the engine, ensuring it is free of old gasket material, corrosion, or debris.
- Position the new pump, aligning it with the mounting holes.
- Install and hand-tighten the new mounting bolts. Then, torque them to the engine manufacturer’s recommended specification.
- Reconnect the inlet and outlet hoses and secure them with the clamps. Ensure the clamps are tight to prevent leaks.
- Open the raw water seacock.
- Reconnect the battery. Start the engine and immediately check the pump and hose connections for any leaks. Confirm that water is circulating through the cooling system.
Troubleshooting & FAQ
How do I confirm this pump fits my specific Yanmar engine?
This pump is specifically for the European-built YEU models: 2GM20-YEU, 2GM20C-YEU, 3GM30-YEU, and 3GM30C-YEU (1996–2004). These engines often have a serial number starting with "E". Double-check your engine model and original part number (128377-42500 or 128397-42500) to ensure compatibility.
What are the common signs of a failing sea water pump?
Key indicators include engine overheating, visible water leaks from the pump housing or weep holes, a noticeable reduction in water flow from the exhaust, or unusual grinding/squealing noises from the pump area. The impeller inside is a wear item and can also fail, leading to poor performance.
How often should the neoprene impeller be replaced?
As a best practice, inspect the flexible neoprene impeller annually and plan to replace it every 1-2 years or approximately every 200-300 hours of engine operation, depending on usage and water conditions. Always follow the specific maintenance intervals recommended in your Yanmar engine service manual.
Is this a direct replacement for my Johnson pump?
Yes, this pump serves as an aftermarket cross-reference for Johnson part numbers 10-24509-01, 10-24509-02, 10-13337-01, and 10-13492-01. Verify your original pump's specifications to confirm a direct fit.
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
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