Carb balancing

[davidball]

Hi my newly acquired 1987 xflow Caterham has two Weber 40 DCOE carbs that may need balancing. Three plugs look a healthy colour but one is much darker and probably running rich. The car has a pronounced cough on even mild acceleration. I was thinking of buying a ColourTune kit and carburettor vacuum gauges (the ones with a plastic pipe). Where do they connect to on the Webers?

[davidball]

Thanks for the advice. I will have to check around. I live in Belgium so I will talk to my friendly garage to see if he knows of one near Ghent.