My overheat sensor is shutting down my outboards (1997 Yamaha 200hp) yet there is a good water flow? Any ideas

Question

My overheat sensor is shutting down my outboards (1997 Yamaha 200hp) yet there is a good water flow? Any ideas

Answer 1

Overboard water indicator only indicates that the pump is funtioning normally, it doesn't tell you whether water is circulating the power head.

If desired, the temp switch can be tested in a pan of water on the stove with a kitchen thermometer, using a multimeter or test light & 12V power source.  You'll need a manual in order to find out the appropriate temp for the switch to close.  Probably neighborhood of 165º F (but don't quote me on that).

Answer 2

Those yrs had problems with the water jackets in the heads plugging up with salt> water flows but not cooling>Have to take the water jacket apart and clean> There is a special note from Yamaha on pre maintenance>In cleaning the haeds>