Take the top off and make sure that the stitch length knob is actually moving the inside the machine and adjusting there. I had one that had sort of frozen up, but with a little oil, and working the reverse button and such, it got easier.
Makitmama, if you are a part of the yahoo group for old singers, you can upload the 227 manual there and others can see it as well. I usually search for a free one for the machines I rescue, because the dollars are limited everywhere, and I like to see if there is anything particular or special about them.