Hi guys, I flew my Score with the K&B ring 61. Using an APC 13/6, engine turning 6800 rpm level, turn engine nose up changed to 8200 rpm. What a beautiful engine, lap time 5.22 seconds, good pull anywhere you want to put her. I have the score tank and she ran over five minutes. With the K&B 61 this ship weighs out at 65 ounces. I have another score with a Merco lite case 61 and she weighs out at 60 ounces. I believe the K&B makes more power and rpm varies a little better than my Merco. Man, what a great day, put several flights on this baby and does she ever fly, Wow. Keep them in the air, Gary