35el79a has a strong tell tail stream, but it appears to be getting too hot when it runs in the lake. Does the tell tail have anything to do with it cooling or not? Could the tstat be bad and causing it to run hot??
tale tell lets you know the impeller is pumping water, it does not indicate that the thermostat is opening and cooling the block. sounds like a bad tstat.
A thermostat that failed in the closed position causes overheat at idle and low speed. A stuck or malfunctioning bypass (poppet) valve causes overheat at higher speeds.
