Mixture screw, removed

Here is the mixture screw laying beside a machinist's rule. When i measured it using my cheap caliper, the needle end was 4mm. long. Given the threaded end (which I think is 0.8mm pitch), the max. adjustment appears to be 5 turns out. The stock adjustment was 2 turns out from fully seated. *NOTE* that there is a spring and O-ring under that screw! If you remove the screw, don't lose the spring or O-ring.