First, make sure the needle is of the right needle system and fully up in the needle clamp. Virtually every home machine in the last 45+ years has used the needle system variously known as 15x1H, HAx1, 130/705H, 130R, SY2020, SY2031, 206x15 and a couple of other names, just for good measure. They're all the same needle system.
Try turning the needle around 180 degrees and see if it fixes it. There's a front and back side to a sewing machine needle. Backwards needles either don't pick up the thread or they skip stitches if they do. Next thing to try is a new needle, right way around. I don't know this machine, but the usual orientation for sewing machine needles is that the flat back of the needle is away from the last thread guide.
Also make sure the bobbin case is in and latched completely.
And if that doesn't work, invert the bobbin in the bobbin case -- if it was sitting in clockwise, try counterclockwise.
Finally, if all that fails, check the timing: http://www.sewusa.com/Sewing_Machine_Rep…
I'm betting on a backwards or bent needle, but if you are still having problems, please feel free to send me an email (click on my avatar, then on email). Some photos of the bobbin case of the machine would help.