>>1476831when they are so rusty its best to turn them slowly
maybe even drip a bit of oil onto the threads
worst case is that the thread is stripped and this along with inadequate cable tension has made the FD sit low
you have what appears to be a top swing front derailleur
the normal problem with them is that they can not get very close to the seat post
given this lesser range of motion they have to be set up with a high initial cable tension
get the bike off the ground or upside down so the wheel rear wheel can spin
if possible shift into the largest chain ring to check that the bottom edge of the outer plate of the front derailleur is no more than 3 mm above the highest tooth
acquire a small wedge shape piece of wood
undo the front derailleur cable
whilst pedaling with one hand use your hands to move the front derailleur in and out between the smallest chain ring (1) and its most adjacent chain ring (2)
determine the distance where the outer plate of the front derailleur pushes the chain down from second to first (newer FD have a dent in the outer plate that does this)
jam the wooden wedge between the inner plate of the FD and the seat post
change the rear derailleur to the third or forth largest cog on the cluster, this is to check if the chain skew can clear your current setting
adjust the lower limit screw clockwise until the FD moves outward (or meets resistance) then loosen it until the FD no longer moves inward due to the wooden wedge
adjust all cable barrels inward all the way (then outward three turns if you want to)
re secure the FD cable wist holding it tight with your hand or a pair of pliers or vice grip pliers, being careful not to crush the cable or pull it too tight
remove the wooden wedge so the FD can take up the cable slack
from then on its just a matter of making very small adjustments
