Defects on the printed objects

Hi I always have defects on my printed objects. Those defects are always on a specific sides of the object I am printing. what could cause it and how do I fix it? here are couple of images.
one side always look good. This was printed with black PLA at 190°c. I am using Simplify 3d.

Hi Maximpop,
it looks like my first tries, when I used the “flow: 90%” setting in Cura.
You may try to reduce the setting in steps of 5%, and see what happens.

I now print with a setting of only 70%, and get very good surfaces and the prints measure nearly perfect.
The problem is: it only works for one of my extruders! The other one needs a higher flow-rate.
I found this solution by try and error, because at my printer I’m not able to move the extruders manually for calibrating this setting.