Balance wheel doesn't move needle
You really should clean and oil/grease the entire thing. Dust, lint, old oil and grease can harden making your machine not run properly. Another thing that may be causing you issues is dried up and gunked up
grease on some inner gears. Take off as many access panels as you can
and use a tooth brush to remove yellowed dry grease from gears, replace
the grease with one made for sewing machines. Lightly grease... just a
little dab will do it. Turn the machine by hand to work the grease
around the gears.
Make sure it's out of bobbin winding mode. Do you remember if you had had to replace the motor belt or had to take the hand wheel off for some reason?
Take the hand wheel off and look for a funny looking lock washer (typically has ears on the outside of the washer and two fingers pointing toward the center of the washer that fits into two grooves) The two fingers are slightly angled... the angled fingers should be pointing OUTWARD when you put it on. This seems counter intuitive but it must be inserted this way for your machine to work correctly. Put it back together and see if it works.
I like to use Liquid Wrench for especially stubborn machines that have been sitting. Don't use WD40 it will free up rusty things but you have to wipe it down well and re-oil. Liquid Wrench is petroleum spirits (kerosene) and graphite, much better for the machine in the long run.