Turnigy Fabricator - Printing narrow Party prolem

[PhilippG]

Hello.
i have aproblem with some printer-settings using ABS.

Every time some pieces of the print are getting narrower, they start to be printed "not solid". Since i have no better description of it, i have attached 3 photos.

Photo 1: http://ablage.gromotka.eu/3dpost/img3.JPG
The piece as seen in Cura.

Photo 2: http://ablage.gromotka.eu/3dpost/img1.jpg
The printed piece after i have stopped the print. Support-material still attached.

Photo 3: http://ablage.gromotka.eu/3dpost/img2.jpg
Supportmaterial is now removed. If you look at the columns, you see that it started to print very poorly. This always happens, when parts of my prints are getting narrower.

I don`t know, what to do about it. Has anybody any input on what setting might be changed to get a better result?

Thanks for any input.

Info about the printer:
It is basically a Ramps/Marlin Board, made into a package by Hobbyking. I am using Cura as a slicer.

@topic:
Curios that my two spelling-mistakes in the title did not get corrected, when i edited this post :-(