Cylinder Head Gasket – Fits Yanmar 6LP Series Marine Engines (Replaces 119771-00421, 119771-00411, 119771-00401)
Cylinder Head Gasket – Fits Yanmar 6LP Series Marine Engines (Replaces 119771-00421, 119771-00411, 119771-00401) is backordered and will ship as soon as it is back in stock.
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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.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cylinder Head Gasket – Fits Yanmar 6LP Series Marine Engines (Repla...
Product Details
This aftermarket Cylinder Head Gasket – Fits Yanmar 6LP Series Marine Engines is engineered for a precise fit across a wide range of compatible models, including the 6LP-ST, 6LP-STE, 6LPA-STP series, and more. It provides a durable, reliable seal for the engine's top end, ensuring optimal performance in diesel applications.
This gasket serves as a direct interchange for Yanmar part numbers 119771-00411 (Mark 3), 119771-00421 (Mark 5), and 119771-00401. It also cross-references to Toyota part 11115-17031-05.
- Installation Location: Engine Top End
- Compatible Fuel Type: Diesel
- Material: High-strength Composite/Metal
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 119771-00411 | Mark 3 |
| Yanmar | 119771-00421 | Mark 5 |
| Yanmar | 119771-00401 | |
| Toyota | 11115-17031-05 | Shared with Yanmar 119771-00421 (Mark 5) |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This part is designed for Yanmar 6LP series marine diesel engines. It is also a shared component with the Toyota 1HDFTE engine.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 6LP-ST | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-STE | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-STZE | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-STZE1 | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-STZY | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-STZYJ | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-WST | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LP-WSTZY | 4-Stroke | 119771-00411, 119771-00421 | Mark 3 (00411), Mark 5 (00421) |
| Yanmar | 6LPA-STP | 4-Stroke | 119771-00421 | Mark 5 |
| Yanmar | 6LPA-STP2 | 4-Stroke | 119771-00421 | Mark 5 |
| Yanmar | 6LPA-STZP2 | 4-Stroke | 119771-00421 | Mark 5 |
| Yanmar | 6LPA-STZP3 | 4-Stroke | 119771-00421 | Mark 5 |
| Toyota | 1HDFTE | 4-Stroke | 11115-17031-05 | Shared with Yanmar 119771-00421 (Mark 5) |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Engine Top End
- Fuel Type
- Diesel
- Housing Material
- Composite/Metal
- Dimensions
- 66.0cm x 18.5cm x 0.1cm
- Weight
- 1 kg (2.2 lb)
- Warranty
- 1 Year (Aftermarket)
- Other Attributes
- Available in Mark 3 and Mark 5 variants
What’s in the Box
- 1 x Cylinder Head Gasket (your choice of 119771-00411 or 119771-00421 variant)
Installation Notes
- Ensure the engine is cool, disconnect the battery, and drain the coolant.
- Remove interfering components such as the intake, exhaust manifolds, and valve cover.
- Loosen and remove the cylinder head bolts in the reverse order of the manufacturer's tightening sequence.
- Carefully lift the cylinder head off the engine block. Avoid using pry bars that could damage the mating surfaces.
- Remove the old head gasket and thoroughly clean both the cylinder head and engine block surfaces. Ensure they are free of any old gasket material, oil, or debris.
- Place the new head gasket onto the engine block, ensuring it is correctly oriented. Do not use any sealant unless explicitly required by the engine manufacturer.
- Carefully lower the cylinder head back into place over the dowel pins.
- Install new or inspected head bolts and tighten them in the sequence and torque stages specified in your engine's service manual.
- Reassemble all previously removed components.
- Refill the cooling system, reconnect the battery, and start the engine to check for leaks.
Troubleshooting & FAQ
How do I know if I need the Mark 3 or Mark 5 gasket?
The correct gasket depends on your specific engine model. Early 6LP engines generally use the Mark 3 (119771-00411), while later 6LPA models use the Mark 5 (119771-00421). Always verify the part number stamped on your old gasket or consult your engine's service manual to confirm compatibility.
What are the signs of a failed cylinder head gasket?
Common symptoms include engine overheating, loss of power, white smoke from the exhaust (coolant burning), milky or frothy engine oil (coolant mixing with oil), or bubbles in the coolant reservoir from combustion gasses.
Does this gasket fit the Toyota 1HDFTE engine?
Yes, the Mark 5 variant (replaces Yanmar 119771-00421) is a direct cross-reference to the Toyota 11115-17031-05 gasket used on the 1HDFTE engine.
Do I need to apply sealant when installing this gasket?
No, this is a dry-fit gasket. Sealants or adhesives should not be used as they can interfere with the gasket's ability to seal properly and may cause premature failure.
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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