I just purchased a 1964 Starcraft boat, motor and trailer. It has 90HP meteor motor. Everything looks in very good shape. I started the motor and it seemed to run good. I had ear muffs on it but could not see any water coming out of the exhaust port at the back of the motor. I shut it off and took the ear muffs off. I've circled the area I had the muffs on. I assumed this was the inlet for the water. I the question mark point to an open hole. Is this the inlet or am I looking at an impeller replacement?