"mechanical" throttle adjustment?
 

I am having trouble adjusting my throttle down the last 200 to 300 rpms. It idles at 1000, but I do not believe it is an electronic problem. When the gas pedal is depressed, the linkage separates a part from the dash-pot sub-assembly. When released, they come back together. If at that point I manually push it in a little further I can get the idle down to 800. As soon as I pull on the linkage and seperate them, when they come back together it idles at 1000. I see there are springs that control the linkage rods. Is it possible mine are worn? Should I attempt to turn the idle screw (actually a nut) to get the idle down? Any suggestions folks?

Scruffboy