Thermostat – Fits Yamaha 60HP/70HP Outboards (Replaces 6H3-12411-11-00)

Thermostat – Fits Yamaha 60HP/70HP Outboards (Replaces 6H3-12411-11-00)

This thermostat is designed for Yamaha 2-Stroke 60HP and 70HP outboards manufactured from 1984–2009. It covers a wide range of models, including Commercial (C), Endurance (E), and Pro (P) series engines, ensuring proper temperature regulation for optimal performance.

This component is a direct replacement for multiple OEM and aftermarket part numbers, providing a reliable solution for maintaining your engine's cooling system.

• Engineered to meet OEM specifications for a direct fit and reliable function.
• Maintains a precise operating temperature of 50°C (122°F).
• Package contains one thermostat, ready for installation.

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 x Thermostat (6H3-12411-11-00)

Installation Guide

1. Safety First: Ensure the engine is completely cool and disconnect the negative battery terminal.
2. Drain Coolant: Drain the engine coolant into a suitable container.
3. Locate Housing: Find the thermostat housing on the engine block. You may need to remove other components for access.
4. Remove Cover: Carefully unbolt and remove the thermostat housing cover.
5. Note Orientation: Pay close attention to the old thermostat's position before removing it.
6. Clean Surfaces: Thoroughly clean the mating surfaces of the housing and cover, removing all old gasket material.
7. Install New Thermostat: Place the new thermostat into the housing in the correct orientation.
8. Reassemble: Position the new gasket and re-attach the housing cover, tightening the bolts to the manufacturer's recommended torque.
9. Refill System: Refill the cooling system with the correct type and amount of coolant.
10. Final Checks: Reconnect the battery, start the engine, and carefully check for leaks as it warms up to operating temperature.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my specific Yamaha engine?

A: First, check the "Compatible Engine Models" table on this page. Match your engine's model, horsepower, and year range. For further verification, consult your owner's manual or use the provided Yamaha Parts Diagram link to visually confirm the part number.

Q: What are the common signs of a faulty thermostat?

A: The most common signs are engine overheating (stuck closed) or the engine failing to reach its normal operating temperature (stuck open). You may also notice erratic readings on your temperature gauge.

Q: What is the operating temperature of this thermostat?

A: This thermostat is designed to open at 50°C (122°F) to begin circulating coolant and regulate the engine's temperature.

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?

• 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.