Home › Forum › Ask A Member › 70hp thermostat compatibilities? › Re: 70hp thermostat compatibilities?
I was able to find a copy of SB 2221, it explains how the heat sensor in the head can cause the motor to go into SLOW mode when the engine is used in water that is above 70°.
Well the river water is currently at 74°, and the motor keeps going into slow mode when left at 4800RPM or above for much more than 10-15 seconds, yet it is not overheating. I have checked in with both a regular prop and test prop and been able to reproduce the same symptom both ways.
Don and Dan have been very helpful, so as not to hyjack my own thread, but it seems I need a new sensor to rule that out as a culprit next. Just glad it isn’t due to aeration on my boat, that would have been disappointing because I can’t change the boat!