My 9.9 4 stroke will run for 20 minutes when it is cold then cough really bad and shut off. I just had a guy put in a new water pump and head gasket in the motor. That cost me $300. I am really frustrated with this motor. It seems to get hot enough that you cannot even put you hand on it for 2 seconds. At the present time there is not a thermostat in it. Any advice would be great, I'm about to throw the thing away!
