If the pulling force is too small, it will not fly/short endurance, and if the pulling force is too large, it will be difficult to control. So I personally recommend using a motor that matches the size of the frame. For example, most 5-inch machines use 2207 motors. If you use 1806, it will be useless (cannot fly or consumes too much power). If you use 2806, it will easily be overpowered (racing machines are not matched like this).