Well...I guess the impeller shot craps...
 

Took the trip down to Table Rock where my boat is stored to winterize it, hooked up the muffs and...no water coming out the exhaust. Tried a few times, decided to dunk it in the lake...same story. Evidently between the last time I had the boat out and it ran/cooled just fine, which was back in July, and now...the impeller shot craps. I have a new complete pump, but just didn't have the time to install it. Going to see if a local mechanic can fix it whilst in the storage unit. In 40 years of boating, I've never had this happen. I guess there is always a first time, huh?

Had the same thing happen to a boat i tried to winterize a couple days ago. Boat ran fine 2 weeks ago, went to winterize and impeller fins broke and siezed the pump up. Had a nice belt squeal when the motor started up

Friend of mine lives at the lake, if you dont find someone I could ask him, is it in Shell knob area ?

I change mine every year - one fall I changed them and they were more worn than I would have expected so I decided I’d always do them annually.

Maybe you got some Chinese knockoffs by mistake?

Yes, Shell Knob area...actually more towards Viola. But I believe I have it covered...thanks!

Yeah, not sure...the shop that did the impeller change last time normally uses only Mercruiser/Quicksilver parts that are (hopefully!) genuine.
I don't put many hours on the boat annually...maybe 15 hours or so, and have only 52 hours on the impeller...so it was ready for a change but the way it failed is something I'd not seen before...usually I'd notice a tendency for the engine to run slightly hotter at idle/no-wake speed if an impeller was bad. My last boat (Baja 208 with a Yamaha 454/Hydra Drive) had a Sherwood pump; I had that boat for nearly 30 years so much more experience with it.

Hope you get it fixed quickly….

One of the problems with having the boat stored 300 miles away...I just can't easily go tinker or work on it.

A few years back I took my brother's boat (502mag) to get hauled . Ran and cooled fine from the slip at the marina to the haul out site.
An hour later on the hard , hooked up the hose to flush out and it wouldn't pump a drop of water . When the impeller was taken out of the pump there was little left of it . That was definitely a wtf moment. So it does happen I guess. .

I always carried a spare seawater pump with me and enough tools to change it. I only remember using it once, but I sure did loan it out a bunch of times.