I have a Magnum 52, Magnum 70, OS 52 and a Saito 45. I have flown both of the 52 in a Lanier Explorer 40 trainer and both were more power than needed. As the specs on the plane call for up to a 70 four stroke, I tried the Magnum 70 in it. I was just trying to do a bit of taxi runs without the wing, and jumping to 1/3 throttle about put the plane in the air without wings. I'm sure I could have pulled it off the ground at 3/4 throttle. Either of the 52 will do well for you. If you budget allows, go for the O.S. as there is a much shorter breakin period. It will idle at 1800 all day straight out of the box where the Magnum is back in the shop to try to get it to idle down reliabily. It doesn't like to play under 3000 rpm. It has had almost two gal through it, so I sent it back for a professional tune. I have no doubt though that it will be as good as the O.S. when this bug is worked out.

One more plus for the four stroke, I can fly it for four flights and only have to clean up the plane to put it back in the car. The 2 strokes leave the thing dripping with oil when it lands. I just put the Saito 45 into a plane I had an O. S. 40 two stroke in and will fly it tomorrow. I'll see if my theory holds.

Don