Shift into the smallest cog, then turn it all the way in and back out. Then, set the cable tension. I just pull the cable snug with my hand and then tighten it down.

Shift once, and turn barrel adj out until it "climbs" into 3rd gear then back in just to the point where it stops "climbing" onto 3. If you look at the derailleur it should be lined up directly under the 2nd cog.

Then shift through the gears. If it won't go into 7th, but does in all the others, try unscrewing the limit screw a tiny bit. 1/8 - 1/4 turn.

Go through the gears again, (many times) and see how that works. Remember, small turns of the barrel adjuster (max 1/4 turns).

L8R