Also I'm trying an experiment. I'm going to see if I can fly a lightened up, NitroModels, Falcon 120 with a Jet Joe Jr. 5 lbs. of static thrust should fly a 10 lbs model. I don't expect to burn up the sky, but it should fly.
Probably a little optimistic. A friend went the lightweight route with the Falcon 120 with a Wren 44 gold (10 pounds) & the performance was not wonderful, the engine spent a lot of time at high power settings just to get it to fly properly. I'ts a big, draggy airframe no matter how light you make it.
I'm flying a Bobcat 50 with a 7 pound Wren 44 & it flys fine, probably a better, low cost option for a 5 pound thrust engine, depending of course that you do, actually, get 5 pounds. - John.