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)

This crankshaft-mounted raw water pump is a direct replacement for Yanmar marine diesel engines, specifically the 2GM20-YEU, 2GM20C-YEU, 3GM30-YEU, and 3GM30C-YEU models manufactured from 1996 to 2004. Please note these are European-built models, often identified by an "E" prefix in the serial number (e.g., E00123).

This pump replaces 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.

• Installation Type: Crankshaft Mounted
• Pump Type: Self-priming flexible neoprene impeller pump
• Package Includes: 1x Sea Water Pump Assembly

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Sea Water Pump Assembly (Replaces OEM #128377-42500)

Installation Guide

Proper installation is critical for performance and safety. Always consult your engine's service manual before beginning work.

1. Safety First: Turn off the engine and allow it to cool completely. Close the raw water intake seacock.
2. Access the Pump: Locate the sea water pump, which is mounted on the crankshaft.
3. Disconnect Hoses: Loosen the clamps and carefully remove the inlet and outlet hoses. Be prepared for some water spillage.
4. Remove Old Pump: Unbolt the old pump from the engine block or mounting bracket.
5. Clean Surface: Thoroughly clean the mounting surface to ensure a proper seal with the new pump.
6. Install New Pump: Position the new pump and tighten the mounting bolts to the manufacturer's specified torque.
7. Reconnect Hoses: Attach the inlet and outlet hoses to the correct ports on the new pump and secure the clamps.
8. Final Checks: Open the raw water seacock. Start the engine and immediately check for any leaks around the pump and hose connections. Ensure there is a steady stream of water from the exhaust outlet.

Troubleshooting & FAQ

Q: How do I confirm this pump fits my specific Yanmar engine?

A: This pump is designed for the European-built Yanmar models 2GM20-YEU, 2GM20C-YEU, 3GM30-YEU, and 3GM30C-YEU made between 1996 and 2004. You can identify these models by the "YEU" designation and often an "E" prefix on the engine's serial number. Always cross-reference your existing part number with the ones listed, such as Yanmar 128377-42500 or Johnson 10-24509-01.

Q: What are the common signs of a failing sea water pump?

A: The most common signs include engine overheating, a reduced or complete loss of water flow from the exhaust, visible water leaks from the pump body or weep holes, and unusual noises from the pump area. The flexible impeller inside is a wear item and the primary cause of failure.

Q: How often should the neoprene impeller be inspected or replaced?

A: As a general rule, impellers should be inspected annually and replaced every one to two years, or more frequently depending on usage hours and water conditions (e.g., sandy or silty water). A worn or damaged impeller is the most common cause of engine overheating.

Q: OEM vs. Aftermarket?

A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?

A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?

A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.