See if this makes sense: If the lower top RPM situation in forward gear is the prop's fault, then could I advance the speed control until it hits that max RPM, observe the speed control lever's position on the engine and, if it's not fully advanced, and further advancement doesn't change the RPM, conclude that either it's too much prop or the engine is down on power from factory specs? Either way, I guess I should somehow mark the control lever's position so I don't feed it more fuel than it can handle, if that makes sense in Dieselandia. It did seem to smoke more than I would expect at full throttle (more than with the old prop, but the engine wasn't fully warmed, either), although I can't remember if that was only in forward. Probably. Even at 2500 RPM, I saw 7.3 knots over water the last time the boat was out, so it's still pushing the boat pretty well.