Cylinder Head Gasket – Fits Yanmar 4JH4E/AE, 4JH5E Marine Diesel Engines (Replaces 129407-01340)
Cylinder Head Gasket – Fits Yanmar 4JH4E/AE, 4JH5E Marine Diesel Engines (Replaces 129407-01340) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Cylinder Head Gasket – Fits Yanmar 4JH4E/AE, 4JH5E Marine Diesel En...
Product Details
This high-quality Cylinder Head Gasket is engineered for Yanmar 4-stroke marine diesel engines, including the 4JH4E, 4JH4AE, and 4JH5E models. It also serves as a compatible gasket for various Yanmar 4TNV88 series industrial engines, ensuring a precise fit and reliable seal.
It is a direct replacement for Yanmar OEM part number 129407-01340 and aftermarket references Y129407-01340 and 12940701340.
- Installation is a direct replacement that requires cylinder head removal.
- Effectively prevents coolant and combustion gas leaks to maintain engine compression and cooling efficiency.
- Constructed from durable, heat-resistant composite gasket material to withstand demanding marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 129407-01340 | OEM Reference |
| Aftermarket | Y129407-01340 | Interchange |
| Aftermarket | 12940701340 | Interchange |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yanmar Marine Engines, this part fits popular 4JH series models. Please verify your specific model is listed.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 4JH4E | 4-Stroke | 129407-01340 | Marine diesel engine |
| Yanmar | 4JH4AE | 4-Stroke | 129407-01340 | Marine diesel engine |
| Yanmar | 4JH5E | 4-Stroke | 129407-01340 | Marine diesel engine |
For Yanmar Industrial Engines, this gasket is used across a wide range of 4TNV88 variants.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Yanmar | 4TNV88-BDHQ | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDHQ(T) | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDSA | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDSA(T) | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDSAC | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDSA2 | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDSA2T | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDWI | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BDYE | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BNYE883 | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BNYE883T | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-BPHB | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-GNP | 4-Stroke | 129407-01340 | Industrial diesel engine |
| Yanmar | 4TNV88-XMS | 4-Stroke | 129407-01340 | Industrial diesel engine |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Direct replacement, requires head removal
- Fuel Type
- Diesel
- Housing Material
- Heat-resistant composite gasket material
- Dimensions
- 40.0 cm x 17.0 cm x 0.1 cm (L x W x H)
- Weight
- 0.5 kg (1.1 lb)
- Warranty
- 6 months (OEM), varies by aftermarket brand
- Other Technical Attributes
- Prevents coolant and combustion leaks; maintains compression and cooling efficiency
What’s in the Box
- 1 x Cylinder Head Gasket (129407-01340)
Installation Notes
- Disconnect the battery and drain the engine coolant completely.
- Remove the exhaust and intake manifolds, fuel lines, and any other components obstructing the cylinder head.
- Remove the valve cover and rocker arm assembly.
- Following the service manual's specified sequence, loosen and remove the cylinder head bolts.
- Carefully lift the cylinder head off the engine block. Avoid using pry tools that could damage the mating surfaces.
- Thoroughly clean both the engine block deck and the cylinder head surface. Ensure they are free of old gasket material, oil, and debris.
- Place the new cylinder head gasket onto the engine block, ensuring correct orientation using the dowel pins. Do not use sealant unless specified by the manual.
- Carefully lower the cylinder head back onto the block and gasket.
- Install and torque the head bolts in the correct sequence and stages as specified by your engine's service manual. This step is critical for a proper seal.
- Reinstall all previously removed components.
- Refill the cooling system, reconnect the battery, and check for any leaks after starting the engine.
Troubleshooting & FAQ
How do I know if my cylinder head gasket is failing?
Common signs include engine overheating, white smoke from the exhaust (indicating burning coolant), milky or contaminated engine oil, bubbles in the radiator or coolant reservoir, and a noticeable loss of engine compression or power.
Is this gasket compatible with both marine and industrial Yanmar engines?
Yes, this gasket is confirmed to fit the specified 4JH series marine engines and the 4TNV88 series industrial engines that use the 129407-01340 part number. Always cross-reference the part number to be sure.
Do I need to use a sealant with this gasket?
Generally, modern composite gaskets like this one are designed for dry installation. Always consult your engine’s service manual for the manufacturer-specific procedure, as some applications may have unique requirements for sealants.
What is the recommended replacement interval?
Cylinder head gaskets are typically replaced only when they fail or during a major engine overhaul. There is no standard periodic replacement interval; they are designed to last for many years under normal operating conditions.
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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