Red light coming on causing engine to go to slow down mode

[Budgetout2]

I have a 2001 25hp four stroke.it is pumping water great but the red warning light comes on and the engine goes into slow down mode.sometimes it takes a while for the light to come on and at other times it comes on right after starting it.what is the procedure for checking to see if the sensor is bad.

[boscoe99]

Yamaha offered seven different F25's for model year 2001. Would you mind telling us which model that you have?

Which sensor are you asking about? The over temperature sensor or the low oil pressure sensor (switch)?