Mercruiser 4.3L + Alpha Drive Not Circulating Water

[boatstuff123]

Some background: After completing a 2 hour boat ride, the tide had gone down and I had to load the trailer in shallow water. During the entire trip, the temp was at 160F. I attached the hose to the lower unit through the ear muffs and went to flush out the salt water. The Problem: There was NO water coming out of the exhaust ports. The temperature creeped back up to 160F, but then continued to 175-180 with no water coming out of the exhaust ports. I stopped the engine. I removed the thermostat and all 4 hoses had no water in them. The thermostat was debris free. I suspect I sucked something up in the shallow water. I had thought even with a worn lower unit water impeller, that the pressure from the hose would circulate the water, leading me to believe there is a blockage. Thanks in advance!

 

[Bondo]

Ayuh,..... Welcome Aboard,...... I guess ya oughta drop the lower unit, 'n change out the impeller, 'n possibly it's housin',.....

 

[boatstuff123]

Will do. Just changed the lower unit fluid, so was hoping to save that for the last step. Wasn't sure if there is anything else that could get clogged. But just learning about the impeller 2-year replacement life, so will change that while I'm in there.