I am not a 4 stroke fan, so lets set the record straight and compare apples to apples. You take a 40 size engine and look at the manufactures prop specs they are just about even for 2 stroke compared to 4 stroke. And I'll guarntee the 2 stroke will out perform the 4 stroke. Don't tell me they pull a bigger prop cause they are always 52 size compared to a 40 2 stroke.