I have a B&S Model 121S07 0065-F1 on a Snapper mower. I cannot get it to idle lower that 2500 rpm. I checked the governor setup and that was correct. The idle screw is all the way out. I did notice that the bracket is slightly bent - see photo.
I must say I am less than pleased with my Stihl 170 chain saw. I bought one because of their supposedly great reputation. I didn't even run a gallon of fuel through the saw and the coil failed. Fortunately it was under warranty. I am probably just starting on my 3 gallon of fuel and the saw...