I measured the bore and stroke-came out of an old stihl trimmer. After putting a 11mm carb on it would run 8050 to 8075 with a 16x8 classic prop. Sorry the above pictures are so big-don't have a clue what happened.
I have a 24 i'm working on that really shows promise. Good shape, real short shaft. I'll post that in a day or two.