This plane is great! I have had one for two summers. It is in bones now and will be repaired by flying season. Mine has an OS 61 in the front. It runs like a scalded dog. Stay away from the 4 stroke 72. This is more for a 46 sized plane! If you go with a 4 stroke go with the 91 or saito 100. But any 61 2 stroke fits perfectly in the cowl. It would be a shame to cut such a beautiful cowl.

Lee