Here's the problem. Boat was in storage for 3 yrs. On first run, got overheat horn and indicated approx. 210 degrees at idle at dock. Immediately shut down engine and replaced pump impeller and housing,(old one looked ok). Then pulled and cleaned thermostats. Looked a little crusty but cleaned up ok and felt smoothe. On next try, engine warmed up to 175 degrees at idle and leveled off. After running at cruise for approx. 5 min., I noticed the temp slowly increasing to about 190 and stablizing. I also noticed the voltmeter had slowly increased from about 13 volts to 16 volts at the same time. I shut the ignition off and back own, the volts indicated 12.5 and the temp went back to 175 degrees. Do I have a volt reg. problem? A temp. indication problem, or a overheat problem? The engine runs great, the water stream is ok, and the exhaust spits out water. Is there a water pressure indicator add on kit available? I heard they're more reliable.