How do I fix the timing on a white 1418 sewing machine?
http://www.sewusa.com/Sewing_Machine_Rep… has some basic methods of checking the timing (and retiming if needed). I’ve run into a number of techs who will tell you that the timing is off on your sewing machine without even checking anything else — there are very few machines that slip out of time without a precipitating catastrophe like the needle hitting the needle plate hard. I, too, suggest replacing the needle (machines are timed with a size 80/12), cleaning and oiling the machine before doing anything further. Make sure the needle is correctly oriented in the machine — a backwards needle won’t pick up the bobbin thread except entirely by accident.