First I don't know anything about the Tin Lizzie, I own a Nolting Pro. The problem could be the thread, needle, batting, fabric, how tight or loose it's loaded, etc. I suggest that you join some general longarm forums or one specific to your TL. I recommend these 2 general longarm forums ... many different longarms are represented. Both are free
http://apqs.com/quiltboard/index.php
http://mqresource.com/forum/