Help! My machine is skipping stitches
 

I had posted a while back that my Federal sewing machine wouldn't sew. I re-wired it, cleaned it, put a new belt on it and put the flat part of the needle going to the left. It finally worked. I was able to fmq a quilt 90x90 with it wonderfully. Then I tried to fmq on my second quilt that's 75x80. I got a third of the way into it when it was skipping stitches. I changed the needle and that didn't work. Any suggestions would help. Thanks!

What size/type of needle do you use in your machine. Try a topstitch 90/14. It could be the combo of the needle and thread. Are you sure the machine is threaded correctly? Try re-threading from the thread spool again.

How is the bobbin thread? Make sure the thread is firm and not squishy on the bobbin.

I haven't used a 90/14 on this machine. I've always used a 100/16. The reason for that size is because my newer Heavy duty Singer sewing machine didn't like 90/14 size. Needles were constantly breaking on me if they were less than a 16. I will have to buy 90/14 size just for that machine. The thread size is a 30. Would that matter in the size of needle?

thread size 30 might be too thick. try size 50.