Need help. I have a 1998 ski nautique with a GT 40 engine. After the oil was changed this spring, went out for a set. Got one pass in and the temp spiked. Boat went into limp mode. Wasn’t getting any water flow after we checked the strainer to insure it wasn’t clogged. Got it back to the dock. Checked the water intake and lines no obstruction. Checked the impeller, seemed to be OK but replaced it anyway. Added a garden nose attachment to the line, could get water to flow up to the thermostat. Ran the boat attached to the garden hose. Temps remained OK, but no water in the manifolds and no water coming out the exhaust. Replaced the thermostat. On the garden hose temps stay low 140 and now a little bit of water coming out the exhaust and in the manifolds but not what I am used to seeing. As soon as I put it in the water and start the boat temps start to spike back the 200. What next? Thanks