Sturtz
Interesting that your 72 handles the 14 X 4w. I tried one on my 46 sized cub and I couldn't get it to turn more than 8700 rpms and it wanted to overheat. I ended up using a 13 X 6 and it flew great. (Scale not 3D) Plane was over 7#s though. I also found that the 14 X 4 wood prop tuned higher rpms that the APC 14 x 4w. Alot heavier, APC is still the best prop for Saito 82 for the UCD.

Thaks Barry for the info on 125 Saito. Maybe I'll hold off and go a little bigger on ST.
Doug