Bumpyroad wrote:
all of those outboards do not recirculate the water. they keep pumping fresh cooling water in. with recirculation you will need a large radiator, fan, etc. I'd like to see a practical design for a portable.
some inboards recirculate the cooling water but have a heat exchanger to dispel heat into the outside/salt water.
bumpy
Radiator size would be small. This is not a problem. The engine would only be running at about 6 hp max (4KW generator), and well below outboard design RPM.
Look at other small water cooled engines, even at considerably more than 6 hp. This would not take a car sized radiator or even a small motorcycle sized radiator. For closest example check out 150 CC scooter radiator (even those are putting down 10-15 hp).
My guess is inverter, liquid cooled, encapsulated engine is the way forward.
