RE: Enya .61
Jeff
The Enya manual lists "BHP 0.9~1.1 @12,500 rpm". Again that's without a muffler. Peter Chinn tested the later and somewhat more powerful Enya III in MAN April 73 and showed .9 hp with the stock carb and muffler. The optional G8 carb on that engine did much better.
This is pure memory (and mine's not that good) but I seem to recall getting 10,500 or a bit more using an 11/7 prop. I normally used a Perry carb and a SilenceAir muffler on my Enya's. This was with the very early Enya 60 II TV.
Tony