GHmarine 66M-12411 Thermostat Repair Kit for Yamaha Outboards (9.9–70HP)

Overview

Keep your Yamaha four-stroke outboard running smoothly with the GHmarine thermostat repair kit. Engine cooling is essential for performance and longevity, and this kit is designed to restore proper coolant flow for engines in the 9.9–70 HP range. The kit emphasizes a crisp fit and reliable materials that many owners appreciate during routine maintenance or on-the-water emergencies.

Why choose this thermostat repair kit?

The components are selected to work together so you can replace worn parts without hunting for mismatched pieces. The thermostat helps regulate engine temperature, the gasket seals the housing to prevent leaks, and the seal provides enduring contact between parts. Together they support consistent cooling performance and easier servicing.

What’s included

• Thermostat 66M-12411
• Thermostat housing gasket 62Y-12414
• Thermostat seal 688-12412

Compatibility and replacements

The kit is designed to replace Yamaha parts 66M-12411, 6G8-12411, 62Y-12414, 6H3-12414, Sierra 18-3541, and Mallory 9-43037. It suits Yamaha 4-stroke engines ranging from 9.9 up to 70 HP, including models like F9.9, FT9.9, F15, F25, FT25, F30, F40, F50, FT50, F60, FT60, and F70.

Real-world uses and benefits

• Pre-season service: refresh cooling components to support steady cooling during busy boating seasons.
• Repair scenario: replace worn thermostat parts to restore stable engine temperature in varied conditions.
• Quick maintenance: a compact kit fits into standard service workflows for boat owners and technicians.

Note: Benefits described here reflect possible improvements in cooling system reliability and maintenance ease rather than guaranteed results. Exact outcomes depend on the engine’s condition and installation accuracy.

About GHmarine

GHmarine designs replacement parts for marine engines with an emphasis on precise fit, durable materials, and straightforward installation. This thermostat repair kit is built to support consistent operation in Yamaha outboard applications while offering value and peace of mind for on-water upkeep.