I do not work for melody. I just remember the TIS systems from years ago that had to have a mechanical advance. I am somewhat of a SME on ignitions systems though. There is not one made that I cannot make work, and work correctly. I have built my own TIS systems in the past and am very glad for CDI now. I have been in this hobby for almost 30 years now. If anyone needs help and will listen I would be glad to help.......