My kenmore is model 158-16250 how old is it
I Have An Older Sears Kenmore Sewing Machine. It Was Working Fine Until I Had To Fill The Bobbin. Now The Tension Is Way Off. What Do I Do To Correct It? It Is A Model 158.13033
Is top thread lose or bottom? Try rewinding another bobbin,it could be bent.if top thread is lose,should be small screw in bobbin case that may need tightening,bottom thread lose, adjust tension dial on outside front of machine, small adjustments at a time.check 4 bent needle and lint build- up around bobbin case.
Another possibility might be that the bobbin was put back in backwards. That will cause the thread to bunch up on the bottom.