3W 24..18-8 prop..6900 rpm..18-6 prop..8400 rpm...
Amsoil 100-1, 7000 feet altitude, 40 degrees temp....
I will advance the timing to see if it gets any better.My first converted Zenoah G260PU turned the 18-6 at 9000 rpm..Is it "top -end" enough ? (Sorry, couldn't resist)

Maybe there's room at the "top"
Update..Same engine, timing advanced, same rpm....
I should have some more 260s and a new Mejzlik prop today, more tests with a real prop.....