So a few weeks ago I had to take my machine to the shop because it's timing was shot!. Well when I got it back it ran awful noisy and just not like my old machine. The cutter didn't work so back to the shop it went. Well I have been busy this week making 120 log cabin blocks and ran out of both bobbin thread and top thread. So I grabbed my old trustworthy joanns spool of thread made a new bobbin and I could not believe how perfect she purred!! (FYI I had not cleaned the machine because I was in the middle of sewing.) I cannot believe that a spool of thread could make a huge difference. I do not want to say what the thread was because I really does work well with my other machines just that my Juki HATES it. So if your machine is running rough try this first I had no idea it would make such a difference!!