Dan;
I run an OS 25 LA on a JK 190. It's a Ball. I did a demonstration years ago with one and took it 50 ft off the tarmac. The announcer then announced I'd crash it into the tarmac and then restart it an take back off. Well! it worked and the thing still flew. Got it back to the pits to examine more damage and the remote needle valve housing was broke, the wing needed a little more strapping tape, and the motor mount absorbing the impact was compressed about a 1/4 in. But!!! it still flew, and crowd was clapping, oh well you get the picture.

BTW the OS 25LA was still a pretty quick engine on that airframe. The roll rate of the JK models are very fast. There just a little pleasure to fly.