Mega Prusa 3dstuffmaker %estrusion and mm/s parameters problems

Hi, a friend of mine gave me a mega prusa to fix, i'v managed to print something but quality is not even satisfying for a printer of this price. The main problem that concern me the most, is the difference between the speed set on the software ( cura ) and the actual speed of the printer, the difference is insane, and the printer just go too fast, a 60mm/s correspons barely a 150mm/s on a standard prusa i3, i have to print at 15mm/s.

If i choose below 30% flow rate i have a print with holes or loosing layers.

Same thing for temperature, under 210° holes and loosing layers and extrusion difficulties.

Firmware is not editable.
Bed is not heated.
3mm pla.
Nozzle is 0.2
I Use Cura.

Edited 1 time(s). Last edit at 02/10/2015 04:00PM by IamTheVector.