Tippysmom,
If you have a gummed up top tension, bobbin case spring, or both, the machine will never sew completely right until that is cleaned.
I don't know about the sewing machine shops in your area, the one locally charges $65.00 to service a sewing machine.
So, if you can read a pattern and make anything from it, you can read the instructions in TFSR and do your own tensions.
{
http://www.tfsr.org/publications/tec...machine_manual }
Why spend money to have something done you can do yourself?
Joe