My sewing machine keeps jamming why

Question

the fabric is being sucked into the bobbin bit, dammit!tried adjusting the tension and cleaning it, help!

Answer 1

Assuming you've done a good job deep cleaning the machine and oiling it per the manual specifications:

Are you hanging on to the ends of the threads for the first couple of stitches in a seam?  

Are you starting far enough from the edge of the fabric (1/4" for most common fabrics) that the fabric isn't being shoved down the needle slot?  

Do you have the correct needle type for the fabric, and is it newish (if more than 4 hours of needle up/down time or you hear "pop-pop-pop" as you're sewing, you need a new needle).

Can you move the needle position to the far right on your machine for straight stitching?

Have you tried stabilizer under the fabric being sewn (tissue paper, adding machine tape, embroidery stabilizer, starch)?

Upper tension should be between 4 and 5 for most fabrics.  Bobbin tension shouldn't need to be messed with except for special effects.  

What's the fabric, type and size of needle you're using, stitch type and length and width?

(I'm betting on bad needle, not holding the ends of the threads and possibly needing a stabilizer)

Answer 2

I had the same problem for a while, then cleaned and oiled it following the manufacturer's recommendations.  It has worked fine since then but is probably due again.  Be sure to completely dismantle the bobbin area to clean it as a lot of lint ends up collecting there.