RE: 3/4 to full throttle no difference while in air????
The torque peak on a G26 is at 9000 rpm, the HP peak is at 12,000.....A prop that will only turn 7000 on the ground is too much load, use less pitch or smaller diameter...
The stock G26 muffler is an rpm killer...You will see around 800 more rpm with a less rectrictive muffler...