Well, yes you can over heat a sewing machine. I had been doing a lot of sewing on my Kenmore, which I'd had for some time, when suddenly there was actual smoke coming out of the sewing machine. Well, I guess I sewed too much for the poor thing, and I had to toss it. I guess someone could have put in another motor, but I opted for a new machine. My girlfriend has the exact same machine and hers is still going strong, but she doesn't do nearly the amount of sewing that I do.