On some of the older Webras, there is a spring loaded screw on the top of the carb next to the venturi. So, what the heck is that screw for??

That fits into a groove in the barrel. It holds the barrel in place and adjusts the idle stop position.

Dr.1

Thanks Dr.1-- Never did use a throttle stop. Kinda like being able to shut-er down w/ the throttle trim. That must be why I couldn't remember what it was for. A 30yr layoff didn't help.