After installing handlebars, and manual trim lever. I can not get the start stop box back on the handlebars. The two bolts on the side closest to the middle screw in fine, but the other side of the box is pulled open (because there is no screw that holds that side together). I am wondering what I am doing wrong here.

There's a locator pin on one half that goes into a specific hole on the stock bars. You'll need to file it down for aftermarket handlebars. If that doesn't do it take it off and look inside to make sure you're not pinching something and that the wiring is tucked up and out of the way. It should sit flush on the bars.