He didn't say what oil or ratio he was using in his other engines. hard to make a comparison call without 1/2 the equation.

Lawnboy, run in a rich engine, as DA recommends, generates a lot of unwanted and unneccessary carbon. There's no reason to run rich unless DA believes their engines to be the equivalent of a glow engine.

DLE is not a DA, and DA does not make DLE. if they did they would have a stronger engine in the same displacement sizes.