[TR] More BS about TRs: throttle return spring

[Brian Jones]

On page 22 of his tome, "More BS about TR's", Bob Schaller has a  
section on an auxiliary carb return spring. The piece finishes: "The  
illustration shows the simple fabrication necessary." But not in my  
case; I must have a several-generations-removed-from-original copy,  
because this image is largely a black blob.

I am imagining a spring attached to the backside of an air filter and  
to the linkage between the carb shafts. If so, is there a piece  
attached to the linkage to give the spring some leverage? Where on the  
linkage does the spring act? Is it on the rear carb shaft, or the  
centre section?

A clear description, or clear photo would be very welcome.

Thanks,

Brian