are you sure the electrical box is working and everything is connected right?
see if you have a charge at the back of the box. If not, it's shot. The Viets love to sell you old boxes. But they're easy to fix, though time consuming. Scrap out all the foam and get to an electrical shop to have the little capacitor, usually that one is burned out, replaced. After you're done just fill it up with wax and let it dry.
If you got a charge get a new wire. And make sure your transformer is grounded correctly, cause if it's a little lose, happens easy on a minsk cause of all the vibration, you only get a charge every now and then, explaining the misfires.
Dalat is good and cheap place to get stuff repaired, the milling shops did some wonders for next to no money when I came through.
Also try to talk to the easy-Rider Guys hanging around there, they were really helpful and brought me to two mechanics who work on their mock-Choppers and therefore can think outside of the Honda-Wave-Box.