I have a world models 71 inch wingspan cub and it is powered with an OS 40 FP. This engine has plenty of power for this plane. It takes off at half throttle and I usulally fly around at half throttle. It will roll and loop with no problem at this power setting. You will probably have to land it with a little power on. My cub lands very wierd not like any of my other planes. It will slow way down like a trainer but the controls become real mushy. If I keep a couple of clicks of power on it is fine.

Rick