I've heard, but am not sure about this, that when a 2-stroke is "4-strokeing" it isn't actually fireing every other revolution, it just sounds like that, it's really an acoustical trick caused by the prop, exhaust frequency, your typical muffler, the raw (liquid) fuel in the exhaust, the cooler exhaust temps, and the human ear's responses to different frequencies. Don't take my word for it though. I read that somewhere, but I forget my source, so I can't go verify that info.

Anyway, as TailDragging said, it means run rich enough that the engine sounds like it's hitting every other stroke, it's pretty obvious, once you hear it, you'll know it.