Thermostat 6F5-12411 For Yamaha 2 Stroke 9.9 15 25 30 40 55 HP Outboard Motor

Thermostat 6F5-12411 for Yamaha

This thermostat (OEM reference 6F5-12411) regulates cooling system temperature for Yamaha 2-stroke outboard motors rated from 9.9 to 55 HP.

Overview

This thermostat for Yamaha 2-stroke outboards helps the engine reach and maintain proper operating temperature. It controls coolant flow to reduce warm-up time and prevent overheating. This thermostat is a direct replacement for the 6F5-12411 part number used across several 2-stroke outboard horsepower ranges.

Built For Performance

• Designed for Yamaha 2-stroke outboard cooling systems
• OEM reference 6F5-12411 for fitment identification
• Responds to coolant temperature to open and close at the correct point
• Constructed for marine environments and saltwater use
• Helps maintain stable engine temperatures during long runs

Fits These Machines

• for Yamaha 9.9 HP 2-stroke outboard
• for Yamaha 15 HP 2-stroke outboard
• for Yamaha 25 HP 2-stroke outboard
• for Yamaha 30 HP 2-stroke outboard
• for Yamaha 40 HP 2-stroke outboard
• for Yamaha 55 HP 2-stroke outboard

On-The-Job Use

• Maintains proper cooling system temperature for Yamaha outboards during trolling and low-speed operation
• Restores proper warm-up behavior in older 2-stroke outboards
• Commonly replaced during cooling system maintenance and winterization
• Used by mechanics when diagnosing temperature-related engine performance issues

Specs At A Glance

Good To Know

Q: How can I tell if a thermostat for Yamaha outboards is faulty? A: Signs include slow warm-up, overheating, or temperature readings that fluctuate. Replacing the thermostat with the 6F5-12411 part helps restore normal cooling operation.

Q: Does this thermostat work in saltwater motors? A: This thermostat is intended for marine use, including saltwater environments. Confirm the serial number and engine model before ordering to ensure a proper fit.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.