The engine is an Ashwameg 25/2 @ 1000 rpm. [reduced to 725RPM]
Anyone have a guess what she will do ??
My 20/2 @ 1000 RPM, reduced to 800 RPM, with an ST-15 makes about/almost 11,000 watts at the limit. So my guess is that your 25/2 engine has a bit more displacement than my 20/2 and with the reduced RPM, of 725, will produce about 18HP. Which should be enough to get 11,000 watts.