Honda 300 no spark

Ok so Honda 300 94 no spark. I can kick start it and it sparks fine if I use starter it will not spark when I left off starter button it will fire one time. I can take the neutral safety wire off and ground it oust starter button while holding the button take the safety wire off ground and it will spark. I have replaced kill switch assy on handle bar neutral switch key switch cdi checked for bad spots in harness and still nothing. Does anyone have any ideas.