i have a Yamaha auto lube 50hp , the problem the engine was not pumping water just steam coming out of the pea hole . i put a new impeller on , the old one was ok .i also connected a garden hose to the water inlet and took of the thermostat of the water flew threw the pea hole fine , i replaced the thermostat with a new one and connected the bottom back on . still not pumping water i know the top section is ok cause i connected a hose to it and i know the rod is connected to the water pump . i am lost any ideas ?