Sea Water Pump Major Rebuild Kit – Fits Yanmar 2GM, 3GM, 2YM and 3YM Series (Replaces Yanmar 128377-42500, 128397-42500)
Sea Water Pump Major Rebuild Kit – Fits Yanmar 2GM, 3GM, 2YM and 3YM Series (Replaces Yanmar 128377-42500, 128397-42500) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Sea Water Pump Major Rebuild Kit – Fits Yanmar 2GM, 3GM, 2YM and 3Y...
Sea Water Pump Major Rebuild Kit – Fits Yanmar 2GM, 3GM, 2YM and 3YM Series (Replaces Yanmar 128377-42500, 128397-42500) is backordered and will ship as soon as it is back in stock.
Product Details
This Sea Water Pump Major Rebuild Kit is designed to overhaul compatible raw-water pumps used on Yanmar marine diesel engines in the 2GM, 3GM, 2YM and 3YM families. It is intended for pumps with a 6-bolt end cover measuring approximately 76 mm (3 in) in diameter.
The kit is offered as an aftermarket replacement for the applicable Yanmar and Johnson reference numbers listed below. Always compare the pump configuration, end-cover bolt pattern and component dimensions with the parts installed on your engine before ordering.
- Complete major rebuild components for a compatible Yanmar sea-water pump.
- Applicable engine families include selected 2GM, 3GM, 2YM and 3YM models.
- Includes an impeller, bearings, seals, end cover, retaining hardware and stainless-steel cover screws.
Part Number Matrix
These references are provided for identification and cross-reference purposes. Confirm the complete pump configuration before installation.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 128377-42500 | Raw-water pump reference |
| Yanmar | 128397-42500 | Raw-water pump reference |
| Yanmar | 128990-42500 | Reference listed for compatible pump applications |
| Yanmar | 128990-42510 | Reference listed for compatible pump applications |
| Johnson | 10-24509-01 | Aftermarket reference |
| Johnson | 10-24509-02 | Reference |
| Johnson | 10-13337-01 | Reference |
| Johnson | 10-13492-01 | Reference |
| Johnson | 10-13328-03 | Reference |
Engine & Model Compatibility
The cataloged pump applications include selected Yanmar 2GM, 3GM, 2YM and 3YM engines. Model suffixes and pump configurations can vary, so verify the pump part number and physical configuration on your engine before purchase.
| Brand | Model Family | Stroke | Applicable Pump Reference | Notes |
|---|---|---|---|---|
| Yanmar | 2GM / 2GM20 family | 4-Stroke | 128377-42500 | Confirm exact model suffix and pump configuration |
| Yanmar | 3GM / 3GM30 family | 4-Stroke | 128377-42500 | Confirm exact model suffix and pump configuration |
| Yanmar | 2GMF family | 4-Stroke | 128397-42500 | Confirm exact model suffix and pump configuration |
| Yanmar | 3GMF family | 4-Stroke | 128397-42500 | Confirm exact model suffix and pump configuration |
| Yanmar | 2YM family | 4-Stroke | 128397-42500 | Confirm exact model suffix and pump configuration |
| Yanmar | 3YM family | 4-Stroke | 128397-42500 | Confirm exact model suffix and pump configuration |
Technical Specs
- Product Type
- Sea Water Pump Major Rebuild Kit
- Installation
- Replacement rebuild components for a compatible pump
- Fuel Type
- Diesel
- Connection
- Direct-mount pump application
- Housing Color
- Black
- End Cover Configuration
- 6-bolt cover, approximately 76 mm (3 in) diameter
- Impeller Dimensions
- Approximately 2 in (50.8 mm) diameter, 0.87 in (22 mm) width, 0.47 in (12 mm) shaft and 6 blades
What’s in the Box
- 1 x Water Pump Impeller (128991-42200 / 128990-42200)
- 1 x Pump End-Cover O-Ring (X02173476)
- 1 x Slinger O-Ring (X02173432)
- 1 x Retaining Ring (X00370012)
- 1 x Retaining Ring (X00371732)
- 1 x Spacer Plate (X0145050)
- 1 x Bearing (X03431760)
- 1 x Bearing (X03431748)
- 1 x Stainless-Steel Screw Set (X0504163)
- 1 x Lip Seal (X02233010)
- 1 x End Cover (X0142398 / 128990-42540)
Installation Notes
- Turn off the engine and close the sea cock or raw-water intake valve.
- Drain residual water from the pump and surrounding hoses.
- Loosen the hose clamps and remove the inlet and outlet hoses from the pump.
- Remove the pump mounting fasteners and carefully detach the pump from the engine.
- Disassemble the pump, recording the order and orientation of the bearings, seals, retaining rings and other components.
- Clean reusable pump parts and the pump mounting surface thoroughly.
- Install the replacement bearings, seals, retaining rings and other kit components using suitable marine-service lubricant where required.
- Install the impeller, end cover and O-ring, ensuring that all sealing surfaces are clean and correctly seated.
- Tighten the cover screws evenly in a crisscross pattern and follow the engine or pump manufacturer’s torque guidance.
- Reinstall the pump, reconnect the hoses and secure all clamps.
- Open the sea cock, start the engine and immediately inspect the pump and hoses for leaks.
- Confirm normal raw-water discharge and monitor engine temperature during the first operating period.
Troubleshooting & FAQ
How do I know if this kit fits my engine?
Check that your engine is a compatible Yanmar 2GM, 3GM, 2YM or 3YM application and compare the pump reference, 6-bolt end-cover pattern and approximately 76 mm (3 in) cover diameter with your existing pump. Model suffixes and pump configurations vary, so do not rely on the engine family alone.
What are the signs that a sea-water pump needs rebuilding?
Common symptoms include water leakage from the pump, reduced raw-water flow, overheating at idle or low speed, worn impeller performance, noisy bearings and leakage around the shaft seal.
How often should the sea-water pump be serviced?
Inspect the impeller at least annually and replace it according to the engine manufacturer’s maintenance schedule and operating conditions. Rebuild the pump when leakage, bearing noise, shaft wear or reduced water flow indicates internal wear.
What is the difference between a major and minor rebuild kit?
A minor kit generally covers routine service items such as an impeller and sealing components. This major rebuild kit is intended for a more complete overhaul and includes internal service components such as bearings, seals, retaining rings, cover hardware and an end cover.
What should I check before installation?
Compare the new components with the original parts, verify the pump reference and confirm the 6-bolt cover and cover diameter. Inspect the pump housing, shaft, cam and mounting surfaces for wear or damage before reassembly.
Can I install this kit myself?
Installation is suitable for a person experienced with marine diesel cooling systems and precision pump assembly. If you are not confident identifying component orientation or setting seals and bearings correctly, use a qualified marine technician.
Is this an OEM component?
No. This is an aftermarket replacement rebuild kit intended for the listed applications and reference numbers. It is not sold as a Yanmar genuine OEM kit.
What are the shipping and warranty terms?
Shipping availability, delivery estimates and warranty or return terms are determined by the store policies shown at checkout and on the applicable policy pages.
Safety & Important Info
- Verify the pump reference, bolt pattern, dimensions and component appearance against your original parts before ordering.
- Close the raw-water intake and allow the engine to cool before removing the pump.
- This is an aftermarket replacement kit, not a Yanmar OEM component.
- Professional installation is recommended if you are unfamiliar with marine cooling-system service.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts selected for dependable service in real-world operating conditions.
- Global Fulfillment — Delivery options and estimated transit times are shown during checkout.
- Manufacturer-Direct Value — Fair pricing with attention to component quality and application details.
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