So I investigated the regulator on the bike. It had moisture in the connectors & a Knick in one of the 3 phase wires (possibly the culprit for moisture ingress).
I also tested the diodes on the regulator all came back in working order. I did the following despite this.
I dried out the connectors installed a new regulator & also installed a voltage display unit into the BMW purchased switched auxiliary lead that powers the Garmin GPS. So two days in and no over voltage yet that said I get a voltage display of either 14.7 or 14.8 at 6000rpm on the motorway and a constant 14.7 through London.
Cheers
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