Singer Model CG500 Skips Sitches?

My sewing machine,Singer CG500, stopped working for me about 2 weeks ago. I had been quilting and suddenly the needle hit an obstruction below. Dead in the water.

I consider myself to be handy, so I got out my tool box, removed the lower cover, and discovered that there's a cogged belt below that connects the hand wheel with the bobbin case. I tinkered with it and got things repositioned to where I could once again sew without the needle hitting the plate.

Now it is skipping stitches-- particularly when going over a stretch of fabric with a straight pin. I continued to tinker with it to no avail. Needless to say this is quite frustrating.

I've gone online (youtube videos) on how to correctly set the timing-- and pretty much all the videos show different models with set screws in certain bars. Well, this model Singer has no bar-- instead it's the belt driven variety.

Long winded here-- wanted to give you enough of a background for someone to diagnose and/or come up with a solution for me.

Thank-you for taking the time to read this, and thanks in advance for a response.