stumped by front derailleur
So here I am in Rabat Morocco and I am one of the very few english speakers with any knowledge of bike repair.
One of my colleagues brought me his kid's mountain bike asking me to true the wheels, adjust the brakes, and tune the derailleurs.
The bike is a Jamis Trail X 1.0 with Shimano Tourney 7spd rear derailleur, shimano undesignated top pull front derailleur, triple crank, and shimano shifter/brake combos that only say 7spd v-brake on them.
The problem is that to get the front derailleur to shift properly the cable needs to be extremely slack. If the slack in the cable is pulled out just by hand so that it is barely taught the derailleur will shift directly from the small ring to the big ring even though the front shifter has only moved one click and is displaying "2". With the cable ridiculously slack (no tension at all) it will shift all 3 clicks and stop properly on the middle ring....but the cable should not be so slack.
I have pulled the cable off the drailleur and adjusted the derailleur height and ensured that it is parallel to the chainrings.
I have pulled the cranks and made sure the bottom bracket (cartridge type) was installed properly. Crank arms were then reinstalled.
For the life of me I cannot get this to work properly.
Resources are scarce here.
Anyone have any ideas?