I had the pleasure of flying two of these wonderful J-3 Cubs today. I have been helping one of my club mates repair and restore one that was passed on to him in poor condition. The airframe has been repaired for some time but we were fighting with an old K&B 61 that came in it and after several test flight days and dead sticks we finally got a full tank flight in with it last week. We declared victory and then did the smart thing and replaced the old K&B with a modern OS 61 FX that I had on the shelf. That's the combo we flew today. It ran and flew flawlessly! We should have made the engine swap to the OS last month but I was determined to not let that K&B win the battle of wills. Once I could declare "victory" over it I replaced it with an OS for ease of operation for the owner. For back to back comparison I then flew my GP J-3 ARF, this one powered by an OS 46 FX. I was always happy with that engine in this plane but I have to admit the extra power with the 61 FX is nice. It gets off the ground (grass runway) much quicker and the climb out is awesome. Very non scale J-3 like but fun. Both combo work well and any day you get to fly two of these is a good day.