Bowden calibration issues?

Hi!

I have no experience at all with bowden setups so I can´t figure out whether my current print problem has anything to do with the bowden setup.

I have a bulldog XL extruder with the thin PTFE tubing (5mm outer diameter) and unfortunately a fake e3d hotend (which I don´t like) but that came with the printer I am testing at the moment.
My real e3d is direct driven 3mm and this printer came with a bowden setup so the hotend does not fit. Also this is the first time I use 1.75mm filament.

What I also don´t like is that the 1.75mm filament has lots of space in the 5mm (outer) PTFE tube that came with the extruder ( the thicker one has 6mm outer diameter).. so maybe my printing issues come from the fact that the
tube is too wide and the filament acts like a spring inside the tube)

Please take a look at the picture... what could be the cause of the problems I have at the corners?

Extruder feedrate is set ok ( I think), x,y and z steps are OK.

Sounds like this kit was thrown together by those with lack of bowden experience

Replace the 5mm tubing with
tubing that is made for 1.75mm filament
and screw in adaptors to extruder and hot end.

Is the inlet in Hot end sized for 1.75mm filament?

Bowden's are squirrelly enough with the right parts!

Yep,the printer came with a bowden extruder for 1.75, 2mm inner diameter PTFE tubing and the 1.75mm "E3D" fake hotend. So all in all a setup that should be useable.

However, the extruder was shit for several reasons, and I have an unused Bulldog XL extruder lying arround, and the choice was obvious that i´ll use the bulldog instead.
However the bulldog came with two sets of PTFE tubing, 6mm outer dia and 5mm outer dia. ( have not measured the inner diameter ).

The hotend only has an snap in inlet for 4mm outer tubing and I had to make the tube´s side of the hotend a bit thinner to use it at all (make it 4mm). But I wonder why the Bulldog extruder manufacturers included such a wide PTFE tube
for 1.75mm applications... ?