Heres the finished product. Turns an 18x8 prop 6600rpm. Not a super powerful engine, but I read the Ryobis dont like a big carb , so I used a small one on this since its made the same way. Notice I used four standoffs and two plates to get the firewall mounting figured out.

It runs well enough, and would be good for a narrow cowl (Spitfire) type aircraft. Never did find out the lawn care product it came out of.