Water Pump Cover Gasket – Fits Yanmar 2GM/3GM/3HM/2QM Series (Replaces 124223-42110)
Water Pump Cover Gasket – Fits Yanmar 2GM/3GM/3HM/2QM Series (Replaces 124223-42110) 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
Water Pump Cover Gasket – Fits Yanmar 2GM/3GM/3HM/2QM Series (Repla...
Product Details
This aftermarket Water Pump Cover Gasket – Fits Yanmar 2GM/3GM/3HM/2QM Series (Replaces 124223-42110) is a genuine-quality replacement for Yanmar marine diesel engines. It is designed for compatibility with the 2GM, 3GM, 3HM, and 2QM series, ensuring a precise seal for the sea water pump.
This part provides a direct interchange for Yanmar OEM part number 124223-42110.
- Material: Constructed from a durable fiber-reinforced composite for longevity in marine environments.
- Installation Type: Standard mechanical fitment for the sea water pump cover plate.
- Important Fitment Note: For 2GM20F engines, two gasket types exist. Please measure your original part's diameter to confirm compatibility.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yanmar | 124223-42110 |
Engine & Model Compatibility
Confirm your engine model in the table below. Note: These parts fit Japanese-built freshwater cooled engines only and are not for European-made models with serial numbers starting with "E".
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 2GM(F) | 4-Stroke | 124223-42110 | |
| Yanmar | 2GM20F | 4-Stroke | 124223-42110 | 2 types, please measure diameter |
| Yanmar | 3GM(F) | 4-Stroke | 124223-42110 | |
| Yanmar | 3GM30F | 4-Stroke | 124223-42110 | |
| Yanmar | 3HM | 4-Stroke | 124223-42110 | |
| Yanmar | 3HM35 | 4-Stroke | 124223-42110 | |
| Yanmar | 3HM35C | 4-Stroke | 124223-42110 | |
| Yanmar | 3HM35F | 4-Stroke | 124223-42110 | |
| Yanmar | 2QM20 | 4-Stroke | 124223-42110 | |
| Yanmar | 3QM30 | 4-Stroke | 124223-42110 | |
| Yanmar | 3JH2L-NE | 4-Stroke | 124223-42110 | |
| Yanmar | 3JH2L-TNE | 4-Stroke | 124223-42110 |
Technical Specs
- Product Type
- Water Pump Cover Gasket
- Installation
- Mechanical
- Material
- Fiber-reinforced composite
- Dimensions
- Outer Diameter: 70mm, 6 holes on 60mm PCD
- Product Dimensions
- 7.0 x 7.0 x 0.1 cm
- Application
- For use with sea water pump cover plates
What’s in the Box
- 1 x Water Pump Cover Gasket (124223-42110)
Installation Notes
- Ensure the engine is off, the battery is disconnected, and the seacock is closed.
- Drain coolant as needed to access the sea water pump.
- Carefully unbolt and remove the water pump cover plate.
- Remove the old gasket and thoroughly clean any residue from both the cover and pump housing surfaces.
- Place the new gasket into position, aligning it with the bolt holes.
- Reinstall the cover plate and tighten the bolts in a star pattern to the manufacturer's recommended torque.
- After reassembly, open the seacock, reconnect the power, and run the engine to check for any leaks.
Troubleshooting & FAQ
How do I know if this gasket fits my Yanmar 2GM20F?
The 2GM20F series used two different gasket sizes. It is critical to measure the outer diameter of your existing gasket or pump cover. This replacement gasket has a 70mm outer diameter. Do not order if your measurement differs.
Will this fit a European-made Yanmar engine?
No. This part is designed for Japanese-built, freshwater-cooled Yanmar engines. It will not fit models with a serial number beginning with the letter "E".
What are the signs of a failing water pump cover gasket?
Common symptoms include visible water drips or leaks around the sea water pump cover, engine overheating alarms, or reduced raw water flow from the exhaust.
When should this gasket be replaced?
It is best practice to replace the water pump cover gasket every time you service the impeller or whenever the pump cover is removed. This helps ensure a reliable, leak-free seal.
Is this an OEM part?
This listing is for an aftermarket replacement component, not an OEM part. It is engineered to meet or exceed OEM-level specifications using comparable high-quality materials and is produced in an ISO 9002 certified facility to ensure quality and consistency.
What are the shipping speed and cost?
We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free. Expedited shipping options, where available, will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our full policy page or contact us for instructions.
Safety & Important Info
- Verify images and specifications against 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 quality control.
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