RE: 45% fuel on a norvel?
My AME is about to hit 20,000 rpm with a 5x3 cox prop. The last time out I use some fuel (25% nitro)that has been opened for several months and it ran 19,000. Today I ran the same brand fuel from a newer bottle and it turned 19,880. It will probably run 20,000 rpm or more after a few more runs.