Originally Posted by countrygent5201
Took another look at the diagram and I am obviously wrong about how the raw water system works. I'll check the lines at the first opportunity and hopefully will find the missing vanes.
Yeah, it pushes the water through, not pulls it.
Back to your original questions:
There's no issue with the impeller and the lack of grease. The boat is just sitting there with the engine off. In fact, I don't even put grease on the impeller blades and have never had an issue (I do occasionally run just a very thin amount of grease around the inside of the impeller chamber, but not every time).
As for the old impeller blades... A bit of a quandary there. They could have broken off intact, or given how old it was they might have even slowly disintegrated in small bits. I don't think anyone can tell you for sure because I don't think anyone has run an impeller that long!
(Actually, I'm skeptical that it was NEVER replaced. Maybe a mechanic took care of it and the previous owner wasn't savvy enough to follow along).
But you haven't said whether your engine is raw water or fresh water cooled (someone else did, but I'm not sure how they reached that conclusion). A "raw water cooled" engine does not have a heat exchanger with anti-freeze reserve. Instead it just pulls raw water from outside the boat and pushes it through the cooling veins of the engine. A "fresh water cooled" boat has a heat exchanger with antifreeze reserve, and simply uses the raw water to cool the heat exchanger.
So the path you have to follow is different depending on what kind of cooling system you have.
For those from the "south" wondering why he'd be discharging anti-freeze, either system is winterized against freezing damage by running non-toxic antifreeze through the "raw water" portion of the cooling system. This gets mixed with and discharged out the exhaust tube.