Smartcraft Gauges

I have a Mercury 2004 135hp Optimax saltwater outboard (with computer system and SmartCraft gauges) has started doing something weird - Start & end at idle, the engine temperature is normal, and the pressure of the water out of the hole good indicator. Then, if I increase gas and start the plane off, I see the engine temperature begins to rise rapidly, and in one minute or if SmartCraft gauge blinks "Reducing the engine speed. When you reduce the speed of return to idle or fast idle, the temperature begins to decrease gradually on the gauge to normal. Yet it continues to pump a water jet high when you run slower or faster. How could he begin to overheat when giving gas and acceleration? Sometimes it will run high rpms and off plan, run entirely normal at a high speed without overheating. I only run the boat about 4 times Twice she did it "overheating and reduce the speed thing" for me and the other two times he ran well at all speeds (normal engine temp). This sense ANY experienced mechanics to Mercury Marine over there? Thank you very much for any help you can provide.

easy solution, make sure the wheel, check dobbers mud nest in the exhaust port, and finally thermostat .... I think the wheel and the thermostat, wouldn, t hurt to R & R a few years both

Have you ever changed the impeller in the water? It could be in a marginal state at this time. Or the water intake could be partially blocked. Thermostat controlled?