I have the "big" version of that ignition system for my 76 Penton. I love the looks on people's faces when they don't see a CDI or points LOL I also like how extremely adjustable the timing is!!!! The Penton has 3 different plates that can be adjusted to advance/retard fire. Mine doesn't have the mini flywheel. It's still STUPID light though.
You may not have a good ground on your ground side of the tether. That could cause it to shoot you lol