Coolant Temperature Issue??

[Reffho]

Hi guys, I have a problem with my FZ6 S2. It’s not overheating, but the temperature is not behaving normally like it used to.

When riding on the highway at around 110 km/h, the temperature stays around 80–82°C. However, as I increase the speed, the temperature starts rising to around 90°C. Even though there is more airflow through the radiator, the temperature keeps increasing.

When cruising steadily at around 130–140 km/h, the temperature reaches around 92°C. When I stop and let the bike idle, the temperature stays around 102–104°C and doesn’t come down, even after the radiator fan kicks in.

I have already flushed the coolant, bled the system, and made sure there are no air pockets, but the temperature is still the same.

Could this be a radiator cap problem or a faulty thermostat?

 

[grahammarsden]

Your coolant temperature sensor (on the back of the cylinder head) could be faulty.

Look in the Yamaha Service or Haynes manuals for the procedure to test it.

 

[Motogiro]

Just a thought...
Had a member who had a Daytona 675 the was over heating. Turn out he had a shop that was going to swap his engine for a used engine because his engine failed.
The shop was doing to well and he brought his bike and used engine home. I swapped the engines and got the bike going again. The first ride was good but as weeks progressed he had pretty high temps. Investigated and the previous shop had spilled motor oil on his radiator. As he road in the coming weeks the oil held on the dust passing through the radiator fins and the radiator lost it's cooling. We washed the radiator out with dish soap to break up the oil and every thing was great again.