Cylinder Head Gasket – Fits Yanmar 6GHA Engines (Replaces 128625-01342)
Cylinder Head Gasket – Fits Yanmar 6GHA Engines (Replaces 128625-01342) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cylinder Head Gasket – Fits Yanmar 6GHA Engines (Replaces 128625-01...
Product Details
This Cylinder Head Gasket is engineered for a precise fit on Yanmar 6GHA series marine diesel engines. It creates a robust seal between the cylinder head and the engine block, effectively preventing coolant and oil leakage while ensuring optimal compression for reliable engine performance.
This part is a direct replacement for Yanmar OEM part number 128625-01342.
- Installation Type: Direct replacement
- Intended Fuel Type: Diesel
- Includes: 1x Cylinder Head Gasket
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yanmar | 128625-01342 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 6GHA-ET | 4-Stroke | 128625-01342 | Marine diesel engine |
| Yanmar | 6GHA-ST | 4-Stroke | 128625-01342 | Marine diesel engine |
| Yanmar | 6GHA-STE | 4-Stroke | 128625-01342 | Marine diesel engine |
| Yanmar | 6GHAK-ST1 | 4-Stroke | 128625-01342 | Marine diesel engine |
| Yanmar | 6GHAM-STE | 4-Stroke | 128625-01342 | Marine diesel engine |
| Yanmar | 6GHD-ST | 4-Stroke | 128625-01342 | Marine diesel engine |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Direct replacement
- Fuel Type
- Diesel
- Compatible Engines
- Yanmar 6GHA-ET, 6GHA-ST, 6GHA-STE, 6GHAK-ST1, 6GHAM-STE, 6GHD-ST
- Dimensions
- 47.0 cm L x 25.0 cm W x 0.1 cm H
- OEM Number
- 128625-01342
What’s in the Box
- 1 x Cylinder Head Gasket (128625-01342)
Installation Notes
- Disconnect the battery and allow the engine to cool completely before beginning work.
- Drain the engine coolant and oil to prevent spills.
- Carefully disconnect all electrical wiring, fuel lines, and hoses attached to the cylinder head.
- Remove the valve cover, followed by the rocker arm assembly and pushrods, keeping them in order.
- Loosen and remove the cylinder head bolts in the reverse sequence recommended by the manufacturer.
- Lift the cylinder head straight up and off the engine block. Avoid prying, which can damage the surfaces.
- Remove the old head gasket and thoroughly clean both the engine block and cylinder head mating surfaces.
- Position the new gasket correctly on the engine block; check for proper alignment with dowel pins.
- Reinstall the cylinder head and tighten the bolts to the specified torque in the correct sequence as per your service manual.
- Reassemble all components in the reverse order of removal.
- Refill the engine with fresh coolant and oil to the proper levels.
- Reconnect the battery, start the engine, and carefully inspect for any leaks.
Troubleshooting & FAQ
How do I know if my head gasket needs replacing?
Common signs of a failed head gasket include engine overheating, white smoke from the exhaust, loss of engine power, or a milky appearance in the engine oil, which indicates coolant contamination.
Will this fit all Yanmar 6GHA series engines?
This gasket is designed for models 6GHA-ET, 6GHA-ST, 6GHA-STE, 6GHAK-ST1, 6GHAM-STE, and 6GHD-ST. Always double-check your specific engine model against our compatibility list before ordering.
Should I use sealant with this gasket?
This gasket is designed to be installed dry. Applying sealants can interfere with its ability to create a proper seal and may cause issues. Always follow the installation guidelines in your engine's official service manual.
What causes a head gasket to fail?
The most common cause of head gasket failure is engine overheating. Other causes can include improper installation, incorrect torque on head bolts, or pre-existing surface imperfections on the engine block or cylinder head.
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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