Complete Engine Gasket Set – Fits Yanmar 3GM30/3GM30F (Replaces 728374-92605)
Complete Engine Gasket Set – Fits Yanmar 3GM30/3GM30F (Replaces 728374-92605) 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).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Complete Engine Gasket Set – Fits Yanmar 3GM30/3GM30F (Replaces 728...
Product Details
This Complete Engine Gasket Set provides all the necessary seals for a full engine overhaul on Yanmar 3GM30 and 3GM30F 27 HP marine diesel models from 1983 and up. It is engineered with high-quality, non-asbestos materials to ensure a reliable, leak-free seal and restore engine performance.
It serves as a direct replacement for Yanmar part number 728374-92605 (which superseded 728374-92600), as well as aftermarket equivalents like Sierra 18-55503 and Hardin Marine 676-18-55503.
- Designed for complete engine rebuilds and overhauls.
- Constructed from modern, asbestos-free materials for safety and durability.
- Includes all essential gaskets for the cylinder head, oil pan, pumps, and more.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yanmar | 728374-92605 | Supersedes part number 728374-92600 |
| Sierra | 18-55503 | Aftermarket cross-reference |
| Hardin Marine | 676-18-55503 | Aftermarket cross-reference |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yanmar | 3GM30 | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30-YEU | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30B | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30C | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30C-YEU | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30F | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30F-YEU | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30FC-YEU | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30FVE | 27 | 4-Stroke | 1983–up | 728374-92605 |
| Yanmar | 3GM30VE | 27 | 4-Stroke | 1983–up | 728374-92605 |
Technical Specs
- Product Type
- Complete Engine Gasket Set
- Installation
- Engine Rebuild/Overhaul
- Housing Material
- Various (Asbestos-free)
- Dimensions
- 45.5 cm L x 29.5 cm W x 2.0 cm H
- Weight
- 0.72 kg (1.59 lb)
- Other Technical Attributes
- Non-asbestos construction
What’s in the Box
- 1 x Cylinder Head Gasket (128374-01911)
- 28 x Assorted Gaskets & O-Rings for complete assembly
Note: Per Yanmar's specifications, certain seals are sold separately. This kit does not include Valve Stem Seals (124950-11340), the Front Crankshaft Seal (121450-01801), or the Rear Crankshaft Seal (124085-02220).
Installation Notes
- Disconnect the battery and completely drain all engine fluids (oil, coolant).
- Thoroughly clean all mating surfaces, ensuring they are free of old gasket material, sealant, oil, and debris. A plastic scraper and a suitable solvent are recommended.
- Inspect all surfaces for flatness, cracks, or warping using a straightedge. Address any imperfections before proceeding.
- Carefully place the new gaskets, ensuring correct orientation. Do not use sealant unless specifically required by your engine's service manual.
- Reassemble the engine components and tighten all fasteners to the manufacturer’s specified torque values and sequence.
- After reassembly, refill the engine with fresh fluids, reconnect the battery, and carefully check for any leaks before returning the engine to service.
Troubleshooting & FAQ
How do I know if this gasket set fits my Yanmar engine?
This set is specifically for Yanmar 3GM30 and 3GM30F series engines (27 HP) made from 1983 onward. The surest way to confirm fitment is to match your engine model to our compatibility list and verify the OEM part number 728374-92605 against your service manual.
Do I need to use sealant with these gaskets?
In most cases, no. These gaskets are designed to create a seal on their own when installed on clean, flat surfaces and torqued correctly. Only apply sealant if it is explicitly required for a specific area by your Yanmar service manual.
Are the crankshaft and valve seals included?
No. Following the original manufacturer's practice for this kit, the front crankshaft seal, rear crankshaft seal, and valve stem seals are not included. They must be sourced separately.
What are the signs of a failed engine gasket?
Symptoms vary but often include engine overheating, milky or discolored engine oil (coolant mixing with oil), white smoke from the exhaust (coolant burning in cylinders), loss of compression, or visible bubbling in the coolant expansion tank.
Is this an OEM part?
This is a high-quality aftermarket replacement, not an OEM component. It is engineered to meet or exceed OEM specifications using comparable materials and is manufactured in an ISO 9002 certified facility with rigorous quality control.
How much is shipping?
We offer free standard shipping worldwide, with a typical transit time of 5–15 days. Expedited shipping options and exact costs are available at checkout if your location is eligible.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. Should an issue arise, please contact our support team with your order details. Returns are accepted within our standard return window for unused items in their original packaging.
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 part, not an original equipment manufacturer (OEM) component.
- Professional installation is strongly recommended for safety, proper function, and engine longevity.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with parts typically arriving in 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
Payment & Security
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