you should just buy a 2015 model
something is definitely wrong with your cluster.
have you looked for kinks and bad bends in the wiring around the steering as the wiring gets clamped to the side of the steering head buy wire guides.
did you check for rubbing and exposed cables that is the protextive black wrap is chaffed.
You have a Mk1, and should be the same, the wiring comes down the LHS of steering and LHS top rail under tank, then makes a 90 deg turn under the rear tank support then another 90 deg turn down the RHS mid section and then back to the ECU.
Potential chaff points are steering neck, and both 90 bends under the rear tank support - the support has sharp edges.
another point is where the wiring goes under the mid section frame cross bar at back of battery and into the rear under seat area.
I would be also pulling the ECU and re-seating the harness a few times... i don't know if it is easier on a Mk1, but on a Mk2 you have to rip the whole back end apart and remove the rear under tray to get that damn ECU out! No way you can just get in there and unclip the harness... it must be freed!