How the hell this thing ever worked is beyond me. The secondary outer carbs must have been coming open at the same time and rate as the primary carb.
Some lazy so and so must have either forgotten to fit them or (more likely) couldn't fit them because there is a knack to it. Anyone with half a brain could work it out but in this case they probably gave up and just fitted the diaphrams without them.
These springs control the opening point and rate of opening of the outer carbs.
It is a good job I had a couple spare isn't it.
