The lower thread tension of my machine is loose
Hi,
I own a Janome sewing machine, I have been using it for more than 12 years. I see that now the lower thread tension is not right, I mean somewhere loose and somewhere tight. I tried tightening the bobbin screw and even adjusted the upper thread tension. I feel there is something wrong with the machine. Is it time for a machie service? I don't undertand, can somebody please helP.....