How do you know your outboard motor is pumping water properly.?

Its a 1975 40hp Evinrude outboard. I have a 89 15hp evinrude and i can see it circulating water and coming out through the spout on the bottom on the motor casing. However the 75 doesn't have the same spout and im not sure where it comes out or if it is even supouse to. I have experiance with newer motors but i haven't dealt with older motors. Any imput would be apperciated.