Cooling issue please help!!!

[25skiffpower]

My 25hp mlh 2009 new motor with only 20 hours out of breakin period. The impeller went last spring resulting in overheating. New water pump kit, new exaust gasket and power head gasket. Ran fine for another 10 hours then winterized and sat for winter. This spring it did have issue of throttle getting a little stuck when trying to get on plane. I attribute this to sticky carb because it got on plane and ran fine just little funny on hole shot. This smoothed out as it warmed up. Then my trouble started, engine took many pulls to start but started and water was pumping. Then as it was warming up I heard it cough. As I looked at the water indicator it was smoking not shooting water, gave it little throttle and no water. I shut motor off and removed cowling, cylinder was to hot to hold without it burning my fingers. I have checked water pump, impeller was in great shape. I shot water up tube and It came out of exaust plate hose connector( I had removed tube leading to indicator). I removed thermostat and checked in heated up water on stove. It worked at 180degrees. I am no outboard mechanic and don't know what else to check.

[Finisher]

Make sure you caught the water tube when you put the lower unit back up. Take the thermostat out, leave the thermostat cover off and start the engine you should get water flowing out of the opening after a few seconds. If you don't then you missed your water tube when you put the lower back up.