Unidentified printing Issue

Hi everybody,

I have a 3D printed since a few moinths now and I still can't get a good print. My machine is a prisa I3 ( like the geeetech one ) and the nozzle is a 0.35mm nozzle from E3D.
I get that "clunk clunk" sound on the extruder sometimes, I saw that the motor isn't strong enough but the current I give him is good enough. So, my guess is that there's too much backpressure in the tip.

This is one of my last print ... I just don't know where I should start changing parameters. Speed ? Infil Speed ? Filament size ? ( 1.70 - 1.73 mm ) ?

I need your advices !
Thanks

Without knowing your parameters it is next to impossible to give proper advise.
Genuine hotend or china clone?
What type of extruder? Geared, direct, worm drive?
Is the printer hardware and software calibrated?
AND: WHAT EXACTLY IS YOUR PROBLEM WITH THE PRINT QUALITY? Don't want to guess that one too....