My Homie 30 is on a mag and it is a "newer" version but I don't know that it's a Ryobi. It was just a bare engine when I got it. I'm pretty sure it came from a blower due to the config of the muffler. There are a couple of things that seem odd. The intake timing is 150 and the piston skirt on the exhaust side is beveled at the bottom so there is a slightly opening to the crankcase from the exhaust port at TDC. That would seem to me to dilute the intake charge limiting power.

The possibility of a limiting coil has been in the back of my mind. I'll try putting a 16x6 prop on it and see if it will turn up more "R"s.