I think it's low too. This is my third Ryobi. It's a new engine from Harbor Freight. My other engines were old and used, but they ran better.

It's spitting out black gunk right now. Still breaking in the rings. I'm going to put a smaller prop on it (16-10 or 16-8) and let it spin up to 7500RPM. Hopefully, that will fly the plane. I'm hoping that if I let it spin up a bit, the rings will seat sooner and the engine will loosen up a bit. It seams pretty low on compression for a twin ring without any compression relief slots in the cylinder. I'm attributing that to the rings being new and not fully seated yet. So, I guess I want the compression to tighten up and the rest of it to loosen up.

I'm also looking for a new carb. The Zama carb has not got a choke plate. VERY hard to start. I can't get my finger in there to choke it--I got big hands. My friend has skinnier fingers, and he has to stick his little pincky finger in there and choke it for me.

I guess if it doesn't come around after a couple gallons of fuel--I'll get the die grinder and the degree wheel out and start checking and hacking.