Mods..
I can certainly see your points regarding mods. I don't want to start boring motors and changing cams or anything like that.
But many times engines, for any purpose, will have to be built to work in any environment they could possibly end up in, or things are made to err on the side of safety. If you know the parameters you're going to operate in, then running them a little closer to the edge may be perfectly safe.
Example would be, mods to make the engine run cooler or breath a little better, etc. On my car project, we went to lower thermostat, distilled water + redline and 20% antifreeze, and 1 step colder plugs, and had some power increases without sacrificing any longevity etc.
I do get your points, though. There probably aren't going to be any major improvements to power output because most of them have been already thought of, and in the marine industry they can push it to the edge a little closer than the car industry due to the different way insurances and emissions, etc would apply. 100hp per liter naturally aspirated is pretty damn good.
Part of the problem is, there are people like me out there that have a build a better mousetrap mentality. Everything that is invented must have something that you can tweak or improve on, and people like me want to find it, even if its obscure or not feasible yet..
So educate me on impellers. Solas makes 2 models that fit the speedster 200. differences? What about switching to a solas impeller and the stainless steel wear ring - less sensitive to weeds and whatnot?