Bobbin tension is too loose

look for lever to adjust feed dog next to bobbin case on the bottom front of sewing machine

here is a link for a free manual that should have the information in it that tell about bobbin tension
http://www.singerco.com/uploads/download/f3eff19dd0b1966512ad6a6bd24e3d8a74926fca.pdf

adjust the top thread tension and see if that helps the bobbin tension
stitches.

here is a link for a free manual for the machine
http://www.singerco.com/uploads/download/545_7470-instruction-book-engfrespa.pdf

the bobbin tension should never need to be adjusted! however, it MIGHT need it, but highly unlikely. check which of them needs changing by sewing a dark thread onto a light piece of material (or vice versa). this makes it easier to see what's happening. any thread which is looped through to the other side is too loose. if a thread is stretched very tightly it needs to be slackened. try to adjust the reel tension first as this is usually the problem.

pucker is caused by too loose or, to tight adjustment of: the thread tensioners both the bobbin tensioner and, the needle tensioner need to be adjusted: to adjust the needle tensioner turn the side knob clockwise is tighter counterclockwise loosens; the bobbin tensioner is a tiny screw on the bobbin holder adjust both tensioners until your stich loops' both top and, bottom are tight but, the machine does not break the thread

Check the buttonhole switch ,if not there there is a microswitch on the bobbin winder that may be out of adjustment

Useful to check the spool and bobbin threading. If either is not threaded correctly, the fabric will pucker/thread will break/loops will appear on either side of the fabric. Easiest to do with machine manual open so as to follow the instructions. Easiest to check your threading each time you change threads by running a test seam on scrap fabric (I keep a large piece of scrap fabric folded in half just for this). More often than not, the problem is with threading. Check threading before you change tension dial or ajust screws. Otherwise, you'll have changed the tension and may still have threading problems. Good luck.

My Singer 7422 seems to be jammed. When I start to make a stitch, the thread from the needle gets caught on something on the bottom and the thread goes over the bobbin.

Hi Tammy,

The problem seems to be with the thred tension adjustment lever/screw (it looks something like 2 inverted disc washers clamping each other thru which a section of your thred passes before going to the puller and then subsequently to the needle guide and then the needle. The fundamental principle of all sewing machins ae the same. Check for the tension. It may have become loose. Also check for the rocker on the inside where you place your bobbin. Are the rocker arriving in syncronisation when the needle is at its maximum in side the knotting hole. If not then there must have been a slight play in the assembly. You alone may not be able to solve all these things. But atleast you know what are the possibilities. I suggest you try only what you can do on the outside. As for the rest, you should refer it to an authorised service person.

Good luck tammy.

Make sure you have the machine threaded for the bobbin and not threaded through the sewing path. Also, check to make sure that the bobbin is pushed directly against the post as far as possible.