40 degrees initial!

I advanced it from 18* initial and idle went steadily up from 850 to about 1000. I was at 40. I turned idle back down to 850 and advanced it more but idle went down at that point.
I guess my thought was if it idled up and the mechanical advancement started to add timing, you could get to 40* pretty quick if you had weak springs. But I doubt at 1000 rpms.