Gasket Kit – Fits Yanmar 6LP-DTP, 6LP-DTZE, 6LP-DTZE1, 6LP-DTZP, 6LP-DTZP1, 6LPA-DTE, 6LPA-DTP, 6LPA-DTZE, 6LPA-DTZP Series (Replaces 930122)
Gasket Kit – Fits Yanmar 6LP-DTP, 6LP-DTZE, 6LP-DTZE1, 6LP-DTZP, 6LP-DTZP1, 6LPA-DTE, 6LPA-DTP, 6LPA-DTZE, 6LPA-DTZP Series (Replaces 930122) 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
Product Details
This aftermarket Gasket Kit – Fits Yanmar 6LP-DTP, 6LP-DTZE, 6LP-DTZE1, 6LP-DTZP, 6LP-DTZP1, 6LPA-DTE, 6LPA-DTP, 6LPA-DTZE, 6LPA-DTZP Series is designed for overhaul maintenance on Yanmar 6LP and 6LPA series 4-stroke diesel marine engines (315–370 HP) manufactured between 1997 and 2007. It provides the essential seals for cylinder head service. Please note that the main cylinder head gasket is not included.
This kit serves as a direct replacement for Yanmar part number 930122 and PoseidonMarine 221040.
- Installation Type: Direct replacement
- Primary Use: Engine overhaul and cylinder head rebuilding
- Fuel Compatibility: Diesel
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 930122 | |
| PoseidonMarine | 221040 | Without head gasket |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is compatible with specific Yanmar marine diesel engines. Please verify your model is listed.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 6LP-DTP | 4-Stroke | 930122 | |
| Yanmar | 6LP-DTZE | 4-Stroke | 930122 | |
| Yanmar | 6LP-DTZE1 | 4-Stroke | 930122 | |
| Yanmar | 6LP-DTZP | 4-Stroke | 930122 | |
| Yanmar | 6LP-DTZP1 | 4-Stroke | 930122 | |
| Yanmar | 6LPA-DTE | 4-Stroke | 930122 | |
| Yanmar | 6LPA-DTP | 4-Stroke | 930122 | |
| Yanmar | 6LPA-DTZE | 4-Stroke | 930122 | |
| Yanmar | 6LPA-DTZP | 4-Stroke | 930122 | |
| Yanmar | 6LP-STE | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 | |
| Yanmar | 6LP-STP | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 | |
| Yanmar | 6LP-STZE | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 | |
| Yanmar | 6LP-STZE1 | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 | |
| Yanmar | 6LPA-STE | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 | |
| Yanmar | 6LPA-STP | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 | |
| Yanmar | 6LPA-STZP | 4-Stroke | Compatible with Head Gasket Mark 1, 3, or 5 |
Technical Specs
- Product Type
- Gasket Kit (Cylinder head not included)
- Installation
- Direct replacement
- Fuel Type
- Diesel
- Dimensions
- 38.0 cm L x 13.5 cm W x 4.0 cm H
- Weight
- 0.27 kg (0.6 lb)
- Other Technical Attributes
- Used for overhaul maintenance and engine rebuilding
What’s in the Box
- 1 x Gasket Set Components (Replaces Yanmar 930122)
Installation Notes
- Consult your engine’s service manual before starting work.
- Disconnect the battery and close the fuel and seacock valves.
- Thoroughly clean all mating surfaces to remove old gasket material and debris. Ensure surfaces are smooth and dry.
- Carefully place the new gaskets, ensuring correct orientation. Do not use sealant unless specified by the manufacturer.
- Reassemble components and tighten fasteners in the sequence and to the torque values specified in your service manual.
- After installation, reconnect the battery and open valves. Run the engine and carefully check for any fuel, exhaust, or coolant leaks.
Troubleshooting & FAQ
Does this kit fit both 6LP and 6LPA series engines?
Yes, this gasket set is designed for a wide range of models across both the Yanmar 6LP and 6LPA series manufactured from 1997–2007. Please check the detailed compatibility table to confirm your specific engine model.
Why isn’t the main cylinder head gasket included?
Yanmar 6LP and 6LPA series engines may require one of three different head gasket thicknesses (Mark 1: 1.0 mm, Mark 3: 1.1 mm, or Mark 5: 1.2 mm) depending on factors like cylinder head machining. This kit excludes the head gasket to ensure you can source the exact thickness required for your specific engine, preventing compression or sealing issues.
What does "decarbonizing gasket kit" mean?
The term indicates that the kit contains the necessary gaskets and seals required for removing the cylinder head to perform service, such as cleaning carbon deposits from the pistons and combustion chambers. It is focused on the "top end" of the engine.
What are the signs I might need to replace these gaskets?
Common symptoms of a failing cylinder head gasket or related seals include engine overheating, a noticeable loss of power or compression, milky-white residue in the engine oil, excessive white exhaust smoke, or visible coolant and oil leaks from the engine block/head joint.
Is this a complete engine overhaul kit?
No. This is a gasket-only kit for cylinder head service. A full engine overhaul or rebuild would require additional components such as pistons, rings, bearings, and other seals not included here.
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.
Payment & Security
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