The bike is a 1985 CB450sc. The carb is not the original so im not sure if it is pre1984 or later. SErial number is vb22gatj. i guess im a little confused on how to set the fuel mixture. I set the idle adjustment screw to 1200rpm. the Fuel mixture screws were turned 2 3/4 at beginning according to FSM. I kept adjusting fuel mixture screw till i saw an rpm drop of 100 rpm then left it there. I then adjusted the idle adjustment screw to 1200 rpm again and then started on the other fuel mixture screw till i saw another 100 rpm drop. Im getting the feeling that i did this incorrectly. I cant adjust the idle screw really either way no without an rpm drop which is a little weird i think. I cant adjust the screw any higher and now it is sitting steady at around 900rpm. Seems to be running pretty well though, it will stall out a little after a high throttle. Im assuming this is because of the low idle? Any ideas?