Nope, those smaller Eskas are air-cooled (small Tecumseh powerheads, like lawnmowers); however, Eska recommended using a TCW-3 grade marine two stroke oil in them despite being air-cooled. That said, I have heard of plenty of guys running them with standard two-stroke oil with no problems. That said, I am not sure about the 3HP models, but the the larger air-cooled models, like the 5 and 7.5HP models, do have an impeller in the lower unit which is used to keep the exhaust leg cool.
