Sadly, yes - that's the same barstard I broke off.
If you're lucky there's enough left of it to grab with some pliers, if you're like me it broke off flush with the carb body...
fyi, it's a fine metric thread screw, NONE of my Briggs/Tecumseh/Holley/Rochester parts carbs had a screw like it... and none of my local shops carry or could get one...I couldn't wait for an internet purchase, so I used a dremel tool with a really thin cutting disk to cut a groove in the remains of the screw (and the carb body around it), then was able to back the remains out, then I re-tapped the threads in the carb body for a mixture screw that I did have. If I could have gotten to the screw straight-on when the carb was mounted on the engine, I might have just used the screw remains (knowing that it might move, not having the anti-vibration spring underneath the now non-existent screw head).
But since Subaru uses a carb that points the idle mix screw RIGHT AT the engine so you'll never get a screwdriver straight on it...


I used to really like Subaru Robin engines...