I have a Glastron MX 175 with the Volvo-Penta 3.0 GLP-C engine. Last year I had to replace the raw water pump housing because the plastic had separated from the brass and it was sucking air and over heated. It was replaced with the solid brass housing. Since that problem, on the first start of the day the temperature will climb over 200 degrees until I rev the engine in neutral to about 4,000 RPM then it will settle between 150 - 175 degrees and be fine for the rest of the day. I've changed the thermostat and impeller and still have the same issue. Anyone have any ideas?