There IS a big difference between 2 stroke and 4 stroke on a 3D machine. The 4 stroke swings a large diameter, low pitch prop with peak power at low RPM. The 4 stroke responds instantly to throttle changes. The 2 stroke swings a smaller diameter, higher pitch prop and power peaks at max RPM. The 2 stroke takes greater RPM and larger throttle changes to get the same thrust as a 4 stroke. I had to see it to believe it.