Mercury water pump question

[Stratusair]

Hi, I have a newly acquired 1969 Merc 4 H.P. outboard. Got it running great but then overheated. Pulled the lower drive and installed a new impeller in the water pump, the old one had no fins left on it. Question is, is the exit water supposed to come out a casting hole in the lower engine cowl like every other outboard I've worked on or does the water exit through the prop hub only? If the water is supposed to stream out the cowl and I don't see any, is it likely I miss installed the water pump tube or are these notorious for blockage when an impeller disintegrates? Any suggestions appreciated.

 

[MH Hawker]

Did you retrieve all of the fins.

 

[Stratusair]

I was able to get a few small pieces out of the base of the pump. Maybe 10% of the total missing. It would help me to know where the cooling water is supposed to exit. Maybe I just don't have the tube connected into the pump.

 

[MH Hawker]

It goes up through the tube into the power head then back down and out the exhaust around the prop, with a bit out the back of the mid section on most motors, not sure on a 4 hp exactly.