Based on previous postings and intuition, I would say you have either an issue with a bad connection somewhere or a power issue.
Power issue is easy- take out the battery, clean the posts and connectors (shine them), same with all the frame grounds and eyes.
As for connections, I am not sure where they all are, but I would disconnect and reconnect each one you find at least twice. At the ECU, to the display, etc. Some are likely to be very hard to get to... so perhaps start with whatever you can easily access and then see if the problem returns and move on to the more difficult ones.