Wow! Thanks so far!
Question - would the bike still run if the PGM was suspect? At Caddy I disconected the powervalve servo and wound the actual powervalves open so I could carry on with the day - the bike ran fine albeit a bit 'gurgly' bottom end!

Also I have actually tried another servo but no luck! Suppose either this servo has also seen its day, or it leads to the PGM being the cause. After all, the original servo was deemed to be a bit 'here and there' by the guy that gave the diagnosis!

Cheers!