My units always need the screen removed from radiator and a pressure air hose to blow them out good, for over heat light indicator alumination that you are noticing with yours . On a day that's (90) degrees under load they tend to run hot anyway ,it seems , but all long as you don`t continue to use them with that light on you should be fine . I have steep grades on my property and when it`s warmer than 75 degrees they throw a lot of heat from engine . They are a very good little unit and the hydro works fine unless you run them low on fluid.As long as it full of 50% anti-freeze it will continue to cool the engine . Slower ground speed and high rpm usually results in cooler running engines , less heat from exhaust valves which is easier to cool.
