Yamaha OEM Thermostats & Covers

The thermostat protects a Yamaha outboard from two kinds of damage: overheating when it sticks closed, and running too cold when it sticks open, which raises fuel consumption, dilutes the oil and speeds up ring and cylinder wear. Genuine Yamaha thermostats are calibrated to the opening temperature Yamaha specifies for each engine family.

This collection holds thermostats, thermostat covers and gaskets for F and T series outboards.

Frequently asked questions

When should the thermostat be replaced?

Inspect it at the interval in your Yamaha owner's manual and replace it any time it fails a temperature test.

Can I use a generic thermostat?

No. Opening temperature and size are specific to the engine family.

Which one fits my engine?

Look up your model in the Yamaha parts diagrams or send us the model and serial number.

The engine still overheats. What next?

Check the water pump impeller, then the rest of the cooling system.

See thermostats for all brands. Boat Max Online is an authorized Yamaha dealer. Free shipping on orders over $149 to the lower 48 states.