Do you have the manual? I have a similar MW zz but not that one. Mine has never acted up like that. UHT-J276 is mine.
Straight stitch says stitch width should be on 2, knob on the upper left.
Stitch selector knob on right is set for straight stitch, the dashed lines.
Mine has a slider on the top lid, and that is also set for straight stitch, the dashed line.
Stitch length is the big knob on the column.
The feed dogs on mine can be dropped by the small knob on the bed. Are yours up all the way? The prob w/ short stitch length, unless your stitch length knob is stuck, can be feed dogs not feeding correctly.
If yours takes cams, maybe a certain cam has to be installed to get the ss and zz correct?
Is the pressure on the presser foot set right?
I will look through my manual to see if there are any other suggestions or troubleshooting. I have not used this machine much at all.
add: Twin needle lever (little silver lever on the lid) set to I, not II, because II is only for positioning a twin needle.
Last edited by MadCow333; 05-31-2013 at 02:57 PM.