Dubbs, these marine engines have a RUBBER impellor in the raw water pump.
This rubber uses water for lube, when new/dry they ship with glycerine, best practice is to prime on jose prior to the first run.
When run dry these chunk/tear. When you then go to the lake and this fails you overheat/strand.
Best is new every year, i pull and reinstall, this kid likely does not know, but ypu trash that impellor and you trash a day.