RE: J3 cub, crash on take off nearly every time.
Ok guys, enough about the engines, it doesn't matter. A plane is only as good as the guy flying it, it doesn't matter if it has a os 40LA or a Saito 82. I flew a Goldberg cub with a O.S. 70 fourstroke and it was a sweetheart, have also flow the same plane with a os 40 fp. Take off roll was only about five feet longer on the forty. More power is great, but not required but will often get you out of a bind when the smaller one won't. The only problem is that when tthe plane gets in a situation that requires more power, they are already over controling the plane and a crash is immenent, no matter what is roaring up front.
I have seen very experienced flyers do the cub snap and eat dirt, it happens! It is up to the builder to decide what he wants up front and what he can afford and so on. In the words of great pilot, fly what ya brung! I won't discourage starting with the cub, I have tought several to fly with cubs and eventually every one of them did the snap but they are all really good pilots now and would probably owe alot to it learning with the cubs. They were Goldberg and Greatplanes kits, nobody had seen many arfs other than trainers and Laneir arfs. Ahh the good old days!! I still am not sold on these cheap china models yet, have not seen one yet I liked but hey, that is another can of worms!