I did do some lightening work to the cast crank but as noted... there was not a lot of excess material to remove.
In the end... I do not see a big performance change from reducing the rotating weight. Yes, the engine does have a different "feel" as it revs-up but it makes about the same amount of horsepower.

My next "test"... use one of the super heavy cranks and the heavy damper and build a high torque combo, then see how that feels, compaired to this "Zing" combo.
DD