50hp 4 stroke

[fshndad]

Does anyone know at what speed (rpm range) does the idle screw operate on?

[boscoe99]

Not sure if I understand the question. The idle speed screw of course is used to set the idle RPM.

The specification for the idle RPM is 750, plus or minus 50. Now one could turn the idle speed screw to be out of specification by more than plus or minus 50 RPM but why would that want to be done?

I presume of course that you have a carburetted F50.