The O.S. 52 will fly it once in the air, however the Saito 70 will get you in the air with less effort especially off grass. I would use the Saito 70 on this plane. I have an 80" H-9 J-3 with a Saito 65 and it is very nice combo. I also have two other 80" size Cubs with 2 stroke O.S. 46 FX engines and they do fly well but the Saito 65 powered one is better. Scale like flights off a grass runway is what I do with my Cubs.