Water not pumping 1962 40HP Seahorse RK-24L

[Hckyjhnsn]

Hey
I have a 62 seahorse 40HP while I was tuning the carb she stop pumping water. Today I replaced the impeller and I’m positive the keys lined up prior to reassembly. Still she’s not pumping water, I cannot think as to why it wouldn’t.
Any help or ideas would be appreciated.

 

[Chinewalker]

Where are you doing the tuning? On a boat in the water or in a bucket? Water level needs to be well above the water pump area as those pumps are not self priming. Also, they can suck exhausts bubbles in a bucket, creating poor water intake, too.