Small Engines (Lawn Mowers, etc.): Stuck Adjusting screw on carburetor, briggs stratton, retaining clip

Question
I have a 23hp v-twin vangaurd engine model 380447  type 0065 with a nikki carburetor. My problem is that I have taken the carburetor off to clean and need to take the idle mixture screw off but it is stuck. I have tried soaking the carburetor, needle nose plyers, screwdriver, ect.  Do you possibly have any suggestions or techniques to be able to get this off.  The other screw comes out easily.

Answer
The only thing I could think of would be a retaining clip on the inside of the passage.  With the carburetor disassemble the see if you can follow the path screwed takes.  If there is a Welch plug remove it.  I would also check for a locking nut on the screw.

If all else fails I suggest stopping at the dealership and asking if they could remove the screw or show you how at least.  If you are purchasing your parts from this dealer I can't see a reason why they wouldn't help you.

I do not have all the different service manuals for all manufacturers engines.  Did you try going to Briggs & Stratton website and searching for a service manual for this engine or this particular carburetor?  The other research could be done at the carburetor manufacturer's website they may have additional information online.  I'm sorry I could not be of more help on this issue.  Best of luck on your project.