Water pump looks ok, but doesn't pump

[FishStretcher]

My water pump quit. It was a little weak 2 years ago. But it has given up the ghost. I took it apart and all the vanes are intact and the stainless housing and plates look ok. All the ports are ok, I can run a wire through them. The impeller didn't spin on the woodruff key.



I will slap an impeller in it and see, but I don't see anything obvious. The impeller is a little bit stiff, that's all. Any thoughts?


This is on a Yamaha F100 from 2000. Last water pump service was 2012. It was due, but I want to see something obvious.


Also I blew air up through telltale and it came out the lower unit. And it peed when on the flush hose.


It will overheat.

[FishStretcher]

I rebuilt it. But the plastic pipe fitting for the speedo hose (which just carries water, right?) broke. I expect I can leave it broken or plug it. Do I have to plug it?

[FishStretcher]

1/8-27 NPT plug solved it