I ran the engine today using omega 10% with extra castor. One 2oz tank, then another 2oz tank and finally a MAS 10x5 GF3 prop.

11,400 RPM @ 500 below peak 2800RPM idle.

as an FYI

K&B Sportster .28 MAS gf3 10x5 @ 11,200 RPM

OS FX .25 MAS gf3 10X5 @ 12,500 RPM