supercedes 61A-85790-00-00

Yamaha - Thermosensor Assembly - Engine Temperature Sensor - 61A-85790-01-00

Overview

This is one of those small parts that does a big job behind the scenes. The thermosensor keeps track of your engine’s temperature and feeds that information straight to your system so everything stays within a safe range. When it starts going bad, you might not notice right away—until alarms go off or the motor starts acting off. Swapping it out is a simple way to make sure your engine is running where it should, especially if you spend long days on the water.

Key Features

• Real-Time Temperature Monitoring – Continuously tracks engine coolant temperature and relays data to the system.

• Engine Protection Support – Helps prevent overheating by triggering alerts or system responses when temps rise.

• Threaded Sensor Design – Installs directly into the cylinder head for accurate readings at the source.

• OEM Precision and Reliability – Built to match Yamaha specifications for consistent performance in marine conditions.

Engine & Boat Compatibility

Compatible with select Yamaha outboard engines and marine applications. Always verify fitment using your engine model and specifications before installation.

FAQ

Q: What are signs a thermosensor is failing?
A: False overheating alarms, erratic temperature readings, or no warning at all when the engine gets hot.

Q: Will a bad sensor affect engine performance?
A: Yes, it can cause the engine to run in protection mode or trigger unnecessary alarms.

Q: Is this hard to replace?
A: Not usually—it threads into the engine, but access can vary depending on your setup.

Q: Do I need to use sealant when installing?
A: Typically yes, a proper thread sealant helps prevent leaks and ensures accurate readings.

Q: How often should this be replaced?
A: There’s no strict interval, but many replace it when troubleshooting cooling or electrical issues.

WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.