You will have cylinder drain at the bottom of cylinders on the starboard side,,,you can go into the pump, and use an air pistol to blow it out..thru the fitting,,.sometimes sand accumulates and can block the drain,,,of course the water will overheat,,,is the inlet cooling line hose secured and clamped?,,also,,with the water connected, and the motor running of course,,look inside the pump cavity, and see if water is leaking where the pump meets the hull,,,sometimes,,the "O" ring can leak,,happens once in a while...this can occur from a bad "O" ring,,,or a pump that is not secured flush with the hull.