728271-92605 Power Head Gasket Set for Yanmar 2GM20 2GM20B 2GM20C 2GM20F | JLM Marine

Power Head Gasket Set for Yanmar 2GM20 2GM20B 2GM20C 2GM20F | JLM Marine

This premium aftermarket Power Head Gasket Set is engineered for Yanmar 18 HP marine diesel engines, specifically designed to fit the 2GM20, 2GM20B, 2GM20C, and 2GM20F models. Built to OEM specifications, this complete gasket set ensures reliable sealing and optimal engine performance during rebuilds and overhauls.

This gasket set directly replaces Yanmar OEM part number 728271-92605 (with 128271-01911) and is cross-referenced as Sierra 18-55502, providing seamless compatibility with your Yanmar marine engine. Manufactured to exact tolerances, it delivers long-lasting durability and dependable service in demanding marine environments.

• Complete power head gasket set for comprehensive sealing during engine rebuilds
• Precision-engineered for Yanmar 18 HP 2GM20 series 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 complete gasket set includes all necessary components for a proper power head rebuild:

• 1 × Power Head Gasket Set (complete with all gaskets required for power head overhaul)

Installation Guide

1. Disconnect the battery and allow the engine to cool completely before beginning work.
2. Remove the cylinder head following your engine's service manual torque sequence and procedures.
3. Thoroughly clean all mating surfaces on the cylinder head, block, and cover using appropriate gasket remover. Ensure no residue or old gasket material remains.
4. Inspect the cylinder head and block for warping, cracks, or damage; resurface or replace components as needed.
5. Compare the new gaskets with the old ones to confirm correct fitment and orientation.
6. Install the new gaskets dry or with a thin coat of gasket sealant as specified by Yanmar service procedures. Do not over-apply sealant.
7. Position the cylinder head carefully onto the block, ensuring gaskets remain properly aligned.
8. Install cylinder head bolts hand-tight, then torque in the proper sequence to Yanmar specifications using a calibrated torque wrench.
9. Reinstall all removed components, hoses, and fittings in reverse order of disassembly.
10. Refill coolant and engine oil to proper levels; check for correct fluid specifications.
11. Reconnect the battery and perform initial start-up, monitoring for leaks or abnormal noises.
12. After the first few hours of operation, recheck head bolt torque and inspect for any coolant or oil leaks.

Troubleshooting & FAQ

Q: How do I confirm this gasket set fits my Yanmar engine?
A: Cross-reference your engine model (2GM20, 2GM20B, 2GM20C, or 2GM20F) with the compatibility table above. Verify your existing OEM part number is 728271-92605 or Sierra 18-55502 to ensure proper fit.

Q: What's the difference between this aftermarket gasket set and the OEM version?
A: This aftermarket gasket set is manufactured to OEM specifications using comparable materials and tolerances. It delivers reliable performance at a more competitive price point while meeting the same sealing and durability standards required for marine diesel applications.

Q: When should I replace the power head gaskets on my Yanmar engine?
A: Replace gaskets during scheduled engine overhauls, if you experience coolant or oil leaks from the cylinder head area, loss of compression, or overheating issues. Always inspect gaskets during head removal and replace as a complete set.

Q: Can I reuse old gaskets during reassembly?
A: No, gaskets are designed for one-time use. Once compressed, they lose their sealing integrity. Always install a complete new gasket set during any power head service or rebuild to prevent leaks and ensure reliable engine operation.

Q: Do I need any special sealant or adhesive when installing these gaskets?
A: Follow Yanmar's service manual recommendations. Some gaskets install dry, while others may require a thin coat of approved gasket sealant. Over-application can cause leaks or gasket failure, so use sealant sparingly and only where specified.

Q: Is this an OEM part or an aftermarket replacement?
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.