I just got done kinda figuring out this combo. I set mine up on an E50, starting first with the 2013 box. In my experience, if it idles but will not rev, flip the flywheel 180°. It's wanting to run backwards, but it fired up forwards, cause that's how it is.
Set it exactly opposite of where the woodruff key would go. Figure out your fire mark again and set it up as you had it.
It clicked for me when one time I started and it kicked back and ran backwards. And it rev'd! So many times of just idle, no power, no rev. Hope this helps.