As I always told my students, there are no bad questions or dumb questions or insulting questions. Just questions. So I appreciate everyone trying to help. It is why I love this community. Knowing you are all out there gives me confidence to tackle problems that don't have YouTube videos to walk me through.
To sum from some earlier questions: 1. I verified that the pump shaft is turning. 2. I am pretty sure the impeller is turning because the pump housing got very hot very quickly from a brief test engine run with no water moving. 3. I can find no obstructions to flow from the seacock to the pump. You comment actually makes me wonder if I have been working under some bad assumptions in doing diagnostics. I had presumed that water would flow rapidly into the raw water pump due to water pressure and the pump would move it along. But as you pointed out, the pump is quite a bit higher than the entry point, so maybe the pressure is fairly neutral there. If I open the seacock, with the cover off the pump, should I see water flowing into the pump? Does the pump simply move water that is already there due to pressure flow, or does the pump actually draw the water into the seacock/strainer by sucking it in? If the latter, then many of my tests have been beside the point and nothing is blocking the flow of water into the boat. It is more that the pump is not drawing the water in, which gets back to the air leak issues mentioned. 1. If it is air leaks in the pump seal, I would propose to use a gasket sealant line Form A Gasket in addition to the o ring to seal the cover? Any reason that is a bad idea? 2. I asked earlier, but is there possibly a pump priming issue? I have never heard of someone having to do anything to prime there raw water pump. I did read an online engine thread where people had this problem with a particular engine, but simply revving the engine got the pump primed and pulling water. Dave David Knecht S/V Aries 1990 C&C 34+ New London, CT
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