H, I am reassembling a Cen NT-16 Rotary Carb and just cant seem to understand how the thottle stop screw works, and keeps the carb open at a certain position when it idles. I have it screwed in, but it makes no sense that when you tighten it the hole opens and lose it the hole closes (or the other way round). All I can see happening is the screw fitting into the groove...

Hope someone can help

Josh

Really not understanding your question. The screw goes into the carb and only allows the throttle to close so far. It's a mechanical stop so the further you screw it in, the soon it will stop the carb from closing thus the larger opening at idle. It's pretty simple.

all sorted thanks

I believe it is also called an Idle adjustment screw.