682-11351-A0 Power Head Base Gasket for Yamaha Mariner 9.9D 15D | JLM Marine

Power Head Base Gasket – Fits Yamaha Mariner 9.9D 15D Outboard Engines

This Power Head Base Gasket is engineered for Yamaha and Mariner 2-stroke outboard engines rated at 9.9 HP and 15 HP. Specifically designed for the 9.9D and 15D engine models produced from 1984 to 1995, this gasket ensures a reliable seal between the power head and the block, preventing coolant and compression leaks.

This aftermarket replacement directly crosses to multiple OEM part numbers including Yamaha 682-11351-A0-00, 682-11351-01-00, 682-11351-02-00, and Sierra 18-99095. It is manufactured to OEM specifications for dependable fitment and performance on your outboard motor.

• Direct replacement for Yamaha and Mariner 9.9 HP and 15 HP 2-stroke engines (1984–1995)
• Ensures proper sealing to prevent coolant and compression loss
• Includes one power head base gasket per package

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. For Yamaha owners, here's a guide to help you identify your engine's serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 × Outboard Power Head Base Gasket

Installation Guide

1. Disconnect the spark plug wire and remove the engine cowling to access the power head assembly.
2. Drain the cooling system and disconnect all hoses and electrical connections from the power head.
3. Remove the mounting bolts securing the power head to the engine block. Carefully lift the power head off the block.
4. Thoroughly clean all gasket surfaces on both the power head and the engine block, removing all old gasket material and residue.
5. Inspect the mating surfaces for warping, cracks, or damage. Address any issues before proceeding.
6. Position the new power head base gasket onto the engine block, aligning all bolt holes and passages carefully.
7. Carefully lower the power head onto the gasket, ensuring proper alignment with all mounting holes.
8. Install the mounting bolts hand-tight first, then torque them to manufacturer specifications in a cross-pattern sequence.
9. Reconnect all cooling hoses, fuel lines, and electrical connections removed during disassembly.
10. Refill the cooling system with the appropriate coolant mixture as specified by the manufacturer.
11. Reinstall the engine cowling and reconnect the spark plug wire.
12. Start the engine and inspect for coolant or compression leaks around the gasket. Allow the engine to reach operating temperature and recheck all connections.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my Yamaha or Mariner engine?
A: Check the Compatible Engine Models table above to verify your engine's horsepower, model (9.9D or 15D), and year (1984–1995). You can also cross-reference the OEM part numbers on your original gasket with those listed in the Part Number Cross-Reference section.

Q: What are the signs that my power head base gasket needs replacement?
A: Common symptoms include coolant leaks around the base of the power head, overheating, loss of compression, white smoke from the exhaust, or coolant mixing with engine oil. If you notice any of these issues, inspect the gasket immediately.

Q: How often should I replace the power head base gasket?
A: Replace the gasket whenever the power head is removed for service or repair. It is a one-time-use component and should not be reused, even if it appears intact, to ensure a proper seal.

Q: Can I reuse the old gasket if it looks undamaged?
A: No, power head base gaskets are designed for single use only. Reusing an old gasket can result in improper sealing, leading to coolant leaks, overheating, and potential engine damage.

Q: What is the difference between this aftermarket gasket and the OEM 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.