The throttle-link idea is an interesting one. I have a Dellorto FZD on my engine so fitted a throttle-link with ball-joints----these are available from "Burlen Fuels" who are in fact, the SU specialist. They can supply link-rods in a variety of lengths, with both left and right-hand threads (one of each, each end). The idea is that you have a ball-joint with a left-hand (female) thread at one end, and a ball-joint with a right-hand (female) thread at the other end of the link-rod. This means that by turning the link-rod, you can extend, or reduce, the length of the link-rod. I found also that by fitting the (male) ball on the UNDERSIDE of the pivot-yoke you get a better 'lead' Removing, and then refitting the link is a few second job. A ball-jointed link also looks very neat.