started out with a 50mm ro and the motor came off 130 and the speedo was 130 the room temp was 85. went to a 51 on the second pack and it was still only about 130. put 3400mahs back in the pack. so I have more power I can use. so I'm thinking of going to the 55 and trying a 2 dot timing spacer. when I can find it. it's in the pile somewhere. play with that tomorrow.