Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Evidently 'Esso Synergy Supreme+ 99' is ethanol free and they sell it at the Tesco garage closest to me.Don't shoot me if I am wrong ... just read about it on another forum.
Also check the rubber pipe between carbs i have seen one where slivers of rubber came off the inside when fitting and messed up float needles
Sounds unusual but our old 1275 S had inch and a half SU's that I changed to inch and a half Stromberg's as they were more responsive and easier to get the mixture right iirc it was an Alexander conversion.