RE: What are you guys flying with the Ryobi 31cc.
Schpankme, Those are very lite motors. I like to weigh mine as "ready to fly".
For instance my Homie 30 is 56.4 Oz. and that includes engine, muffler, ignition system, battery, switch, linkages prop nut and washer and whatever it takes to mount it. Everything except prop and spinner.
Ron