I just had maintenance done on my primary machine a couple weeks ago, and I had the timing fixed. Then yesterday, I tried out my new ruffling foot . . . and it offset the timing on my machine! Maybe I'm just not using the foot properly? But it seems clunky and slow and bad and awful.
Luckily, it doesn't take a rocket scientist to fix the timing on a sewing machine. Last week, it became apparent that the timing on my backup machine was off too. Since I had just dropped $60 getting maintenance on my primary machine, I wasn't eager to bring another machine in. So, I did a little search on youtube and busted out the screwdriver. (If you're sans screwdriver, the Mastercraft 15-piece Flexhead Driver is a dream!)
If you ever find your needle making clicking noises, like it's hitting metal. Or your threads are tangling or not catching, despite perfect tension settings, you may have a timing problem. These videos can save you! I had to take into account that my machine is built a little differently, and I had to pause them about a million times, but I finally got 'er done. I saved myself some cash and got to feel like a DIY hero, so high five to that.