Well, here's what I'm going to do. I'll make a test stand for my YS120 to run it and measure thrust. I have a Zinger18x6 that I'm going to modify, like I modified my Zinger16x6 for my YS91. When the YS120 pulls it at 9-9.5k I'll see how much thrust I have. If I get 15 lbs or more, I will look for the lightest Cap232 120 size available. That looks like the World Models, but I'll call around and see how much fuse, wing and hardware weighs on the different models, and add the 2 lbs engine and the weight of radio gear etc. If I can get it all at 10 lbs I'll go for the 120 size.
DKjens