Power Head Gasket Set – Fits Yanmar 1GM 7 HP Marine Engine
This professional-grade Power Head Gasket Set is engineered for Yanmar 1GM 7 HP marine engines, delivering a reliable seal for your power head assembly. Designed to meet the demanding requirements of marine environments, this gasket set ensures optimal compression and prevents fluid leaks during engine operation.
Direct Replacement for: Yanmar Marine Part Number 728170-92600 (with 128170-01331) and Sierra Marine Part Number 18-55500.
- Complete power head gasket set for comprehensive sealing
- Precision-cut gaskets for proper fitment and performance
- Suitable for routine maintenance and engine rebuilds
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
Notes |
| Yanmar Marine |
728170-92600 |
Includes 128170-01331 |
| Sierra Marine |
18-55500 |
Aftermarket equivalent |
Compatible Engine Models
Confirm your engine model/year in the table below.
| Brand |
Model |
Rated HP |
| Yanmar Marine |
1GM |
7 HP |
Technical Specifications
| Specification |
Value |
| Product Type |
Power Head Gasket Set |
| Application |
Marine Diesel Engine |
| OEM Reference |
728170-92600 |
Package Contents
Your package includes:
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1 × Power Head Gasket Set (complete set with all necessary gaskets for power head assembly)
Installation Guide
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Preparation: Disconnect the battery and allow the engine to cool completely. Gather all necessary tools including torque wrench, scraper, and cleaning solvent.
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Disassembly: Remove the cylinder head following your engine's service manual specifications. Keep all fasteners organized for reassembly.
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Surface Cleaning: Thoroughly clean all mating surfaces using a gasket scraper and solvent. Ensure no old gasket material, carbon deposits, or debris remain.
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Inspection: Inspect cylinder head and block surfaces for warping, cracks, or damage. Use a straightedge to verify flatness; resurface if necessary.
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Gasket Positioning: Position the new head gasket on the engine block, aligning all bolt holes and water passages correctly. Do not use additional sealant unless specified by manufacturer.
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Head Installation: Carefully lower the cylinder head onto the block, ensuring gasket alignment is maintained. Install all head bolts finger-tight initially.
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Torque Sequence: Tighten head bolts following the manufacturer's specified sequence and torque values in multiple stages. Use a calibrated torque wrench for accuracy.
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Remaining Gaskets: Install remaining gaskets from the set according to their designated positions (exhaust, intake, covers, etc.). Replace all sealing surfaces simultaneously.
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Reassembly: Reconnect all components, hoses, and electrical connections removed during disassembly. Double-check all fasteners are properly tightened.
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Fluid Refill: Refill engine coolant and oil to proper levels. Check for correct fluid types per manufacturer specifications.
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Initial Start: Start the engine and allow it to reach operating temperature while monitoring for leaks. Check coolant and oil levels after initial run.
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Re-torque: After the first heat cycle, consider re-torquing head bolts per manufacturer recommendations. Monitor engine performance during break-in period.
Troubleshooting & FAQ
Q: How do I confirm this gasket set fits my Yanmar 1GM engine?
A: Verify your engine model number stamped on the engine block or data plate. Cross-reference the OEM part number 728170-92600 with your engine's parts manual to ensure compatibility before ordering.
Q: How often should I replace the power head gasket set?
A: Replace gaskets whenever the cylinder head is removed for service, repairs, or overhaul. Gaskets are single-use components and should never be reused, as they lose their sealing ability once compressed.
Q: What are the signs that my power head gaskets are failing?
A: Common symptoms include coolant leaks around the cylinder head, white smoke from exhaust (coolant burning), oil contamination in coolant or vice versa, overheating, loss of compression, and rough engine performance.
Q: Can I reuse the old gaskets if they look intact?
A: No, never reuse gaskets. Once compressed during initial installation, gaskets conform to surface irregularities and lose their ability to seal properly if removed and reinstalled, even if they appear undamaged.
Q: Do I need to apply sealant to these gaskets during installation?
A: Typically, no additional sealant is required unless specifically called for in your engine's service manual. Modern gaskets are designed to seal properly when installed on clean, flat surfaces with correct torque specifications.
Q: OEM vs. Aftermarket?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.