At last! I finally managed to resolve the ignition fault on my Aprilia Futura yesterday after installing a new set of leads and replacing an ignition coil. The new set of ignition leads from Magnecor are a lot easier to position within the limited space, and offer improved performance above the standard leads. On further investigation I also noticed that one of the ignition coils had a small crack in the insulation, which allowed it work without problem when testing away the coil mount, but would fail when installed on the mount because of arching against the frame.
After several tests using the TuneECU software the ignition circuit is working correctly, and no fault codes being reported. The next job is to refit the bodywork and go for a test ride. I think I also received some good luck from a mystery black cat who appeared in my garage whilst I was working 🙂