[Tony Wheeler]

Lynn, I believe most if not all 8BA dizzy complaints arise from having changed the carby, or fitted multiple carbies. This eliminates the venturi vacuum system which is built into the original carby, leaving only manifold vacuum to control the diaphragm. The two systems were designed to work in tandem, so if the venturi vacuum is disconnected, or split across more than one carby, the dizzy needs to be completely recalibrated. I suspect this is not well understood amongst rodders and often gets overlooked, so the dizzy itself gets blamed. Which is hardly surprising as it's radically different from the earlier vaccum system on the crab, which can be disconnected without noticeable effect.