Slant 6- Idle and Running

no, warm motor will cause choke to pull off that step once you tap the gas pedal...its spring cocked like a gun. Once the bimetallic spring is warm, that stepped cam will rotate right off that step to base idle once you tap it. (itll stay on that forever if you dont tap the gas). Once the cam is out of the way due to the choke being warm, it should rest on base idle, that's where you set your 750 RPM. If you want to do it manually, just manually move choke off on a warming engine (manipulate choke rod while releasing that stepped throttle stop) It will be under a little spring pressure but that will relax when the choke spring is warm (you could actually heat the choke spring with a blowtorch and it would pull of just like a warmed engine, Id use a heat gun but manually doing it is easy). Those choke linkages get sloppy over time, dont expect them to be precision rotating. There is a bleed half way down the throat that leads to the mixture screw passage, make sure that is clear. Take mixture screw out and shoot carb cleaner into the bleed and see if it comes out the screw hole. Wear glasses! Return screw to light seat then back out 1.5X for baseline. Might want to make sure the throat is clear of sludge where the butterfly hits the venturi also.