Top thread tight
 

My 221 sews a perfect seam, but when I finish and pull the threads to cut them, the top thread is really tight, so tight that it nearly gathers the fabric. I've tried the upper tension on several numbers and it doesn't change.

What could the problem be??

Your bobbin is too tight. Take out the bobbin case and turn the screw to the left (leftie Lucy) about 1/8 of a turn. Try it. Still too tight? Another 8th of a turn and so on. Don't be afraid of that screw. That is why it's there.

It sounds like your top tension isn't releasing when you lift the presser foot.

This is where I would start too.
Rodney

A friend told me to jiggle the handwheel back and forth a tiny bit (tiny!). Then try. Or, bring the wheel a little farther forward than you think you need to (ie, needle is on its way back down) - that will release the top tension.

Worked for me!

I'm with Macybaby and Rodney. I start by verifying the top tension is releasing when you raise the presser foot. I'll bet the little pin is stuck or there's some other problem.

Joe

I routinely take the tension off and rebuild. Then I take the bobbin spring off off the bobbin case and clean it off. I adjust them both. Usually that solves the problems.

I do what Miriam does. I've run into this a few times. I use a plain white string and floss through the thread guides to be sure nothing's catching. Then take the top tension apart clean it well and put it back together. That usually solves it.

I've learned the hard way do both the top and the bottom. There is usually dried oil on the pin in the tension, too. That's why I pull it.

I'm scared to fool with the tension dial thingy, afraid I will not be able to get it back on! I will check out the other things you all suggested and see what happens.