Yamaha – Thermostat | Engine Cooling System Component | 6EK-12411-00-00

Overview

If you spend enough time working on Yamaha four-strokes, you learn pretty quickly that the cooling system is everything. This Yamaha thermostat helps regulate engine temperature so the motor warms up properly and stays within its designed operating range. When it opens and closes the way it should, the engine runs smoother, burns fuel cleaner, and avoids unnecessary wear. It’s a simple service item, but replacing a tired thermostat is one of the easiest ways to keep a Yamaha running the way it should.

Key Features

• Temperature Regulation Control – Opens and closes based on coolant temperature to maintain proper engine operating conditions.
• Optimized Engine Performance – Helps the motor reach and maintain its designed running temperature for efficient combustion.
• Genuine Yamaha Construction – Built to Yamaha specifications for correct fit and reliable cooling system operation.
• Routine Service Component – Common replacement item during cooling system maintenance or overheating diagnosis.

Engine & Boat Compatibility

• F115 - 2014-Current
• LF115 - 2014-Current
• VF115 - 2015

Frequently Asked Questions

Q: What are signs that the thermostat may need replacement?
A: Common signs include the engine running too cold, overheating, or fluctuating temperature readings on the gauge.

Q: How often should a thermostat be replaced on a Yamaha outboard?
A: Many technicians check or replace thermostats during routine cooling system service or every few seasons depending on use.

Q: Can saltwater use affect thermostat life?
A: Yes. Salt buildup and corrosion can affect thermostat operation over time, which is why periodic inspection is important.

Q: Is thermostat replacement a difficult service job?
A: On most Yamaha outboards it’s a straightforward maintenance task that can be done with basic tools.

Q: Should thermostats be replaced when servicing the water pump?
A: It’s not required, but many boat owners choose to inspect or replace them at the same time since both are part of the cooling system.