That hinge point (and the starting position of the pinch bolt) determines whether the top or the bottom of a cam within the lever assembly is making contact with the throttle spindle at the beginning of the throttle movement. My carbs were set up so that the moment the main throttle linkage was moved, the front two carburettors throttle spindles began to rotate immediately, whereas on the rear carb, it had to wait for the cam to move within the lever assembly with the result that the spindle only began to move once the throttle linkage had moved a couple of millimetres. That was obviously not correct, so I adjusted the pinch bolt so the rear carb also acted immediately upon the movement of the main throttle linkage commencing.
After the long preamble above, my question is straightfoward. Should the three carbs pinch bolts be set up so that the lever assembly cams only permit movement of the carburettor spindles once a couple of mm travel of the main throttle assembly has taken place or should they be set that the spindles start to move the moment the main throttle linkage moves. The former provides for some degree of tolerance in case the main throttle linkage does not return fully to its starting position whereas the latter provides for instantaneous response.
