Easiest forum to join and use that I've come across . Can you get a close up of all these carb pipes so I can compare them to mine and see which ones you can lose ? I'm guessing from the pics that the original vacuum tap is not on the bike . On ERs its actually on the frame not the tank so I reckon that the pipe that links the carbs is blanking off the vacuum line . Anyway,let's have a look and take it from there . Can you describe these poor running characteristics as well please ? Cheers . PS I already had this photo, what you see is a vacuum pipe from the right carb coming over to the tap and on the left carb a bung in the centre of the picture that simply blanks it off . I'm guessing that on your bike , rather than buy another bung someone has just attached the pipe to the other carb . These are the points , by the way, that you fit guages to when you sync the carbs . To be honest, I don't think this is a great idea to link the carbs . I reckon two bungs would be better.