728374-92605 Power Head Gasket Set for Yanmar 3GM30 3GM30F | JLM Marine

Power Head Gasket Set for Yanmar 3GM30 3GM30F | JLM Marine

This Power Head Gasket Set is engineered for Yanmar 27 HP marine diesel engines, specifically the 3GM30 and 3GM30F models (including EU variants). It provides a complete solution for top-end overhaul and rebuilding applications, ensuring proper sealing and reliable performance in marine environments.

This gasket set directly replaces Yanmar OEM part number 728374-92605 and Sierra part number 18-55503, offering a cost-effective alternative for professional mechanics and DIY enthusiasts maintaining Yanmar marine diesel engines.

• Complete power head gasket set for comprehensive engine sealing
• Designed for 27 HP Yanmar 3GM30 and 3GM30F marine diesel engines
• Direct replacement for OEM and aftermarket part numbers

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

This package includes the following component:

• 1 × Power Head Gasket Set (complete set for engine overhaul)

Installation Guide

1. Disconnect the battery and allow the engine to cool completely before beginning work.
2. Remove the valve cover, exhaust manifold, and any other components obstructing access to the cylinder head.
3. Carefully unbolt and remove the cylinder head, keeping track of bolt locations and torque sequences.
4. Clean all mating surfaces thoroughly, removing all traces of old gasket material and carbon deposits. Use a plastic scraper to avoid damaging metal surfaces.
5. Inspect the cylinder head and block for warping, cracks, or damage; resurface if necessary.
6. Place the new head gasket onto the engine block, ensuring proper alignment with dowel pins and bolt holes.
7. Carefully position the cylinder head back onto the block, aligning it with the gasket and dowel pins.
8. Install head bolts and torque them to manufacturer specifications in the correct sequence (consult your Yanmar service manual).
9. Install remaining gaskets from the set according to their respective positions (valve cover, manifold, etc.).
10. Reassemble all removed components in reverse order of disassembly.
11. Refill coolant and engine oil as needed, then reconnect the battery.
12. Start the engine and check for leaks; allow it to reach operating temperature and verify proper operation.

Troubleshooting & FAQ

Q: How do I confirm this gasket set fits my Yanmar engine?
A: Cross-reference your engine model with the compatibility table above. This set fits 3GM30 and 3GM30F models (including EU variants) rated at 27 HP. Verify your original part number matches 728374-92605 or Sierra 18-55503.

Q: What's included in the power head gasket set?
A: The set includes all necessary gaskets for a complete power head overhaul, including head gasket, valve cover gasket, and associated sealing components required for top-end rebuilding.

Q: When should I replace the head gasket on my Yanmar diesel?
A: Replace the head gasket if you notice coolant in the oil, white exhaust smoke, overheating, loss of compression, or external coolant leaks. Always use new gaskets during any cylinder head removal or engine overhaul.

Q: Do I need any special tools or sealant for installation?
A: You'll need a torque wrench and the proper torque specifications from your Yanmar service manual. Most gaskets install dry, but check your manual for any specific sealant requirements on certain components.

Q: What are the signs of a failing head gasket?
A: Common symptoms include coolant loss with no visible external leaks, milky or frothy oil, overheating, rough idle, white exhaust smoke, and loss of power. Address these issues promptly to prevent engine damage.

Q: Is this an OEM or aftermarket part?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.