Ended up getting a vacuum gauge and adjusting the air/fuel mixture screws on the carb for max vacuum. Then we adjusted the timing to ~17-18". Did this a couple times and adjusted the idle down each time. Rpms are now at 900 - a lot better than the 1500 we had to keep it running earlier. The dying problem is gone, though - it would probably run until the tank ran dry. Starting can be a little tricky, but that's what I'm working on now. It will start, but needs a lot of pedal action. Main point - it doesn't die anymore once the timing was adjusted and the air/fuel mixture adjusted. We had to adjust the timing as high as we did because he have a good-sized cam.