ORIGINAL: armody
As I read in the prop charts I read these are the right sizes for your 4 stroke .72CI engine.
0.63-0.72 12x7, 12x7~9, 13x6~7, 4-Stroke Glow, 10000~11000rpm
Mody
The above prop numbers are the factory recomendations for sport and scale flying. How do
YOU want to fly your Twist? The 13x4 will be good for 3D flying but based on the factory numbers I would even look for a 14x4 as a possible prop for even better 3D performance. I experiment with props but the down side to that is I end up with props I don't use