silly sloth

I have 2 1985 Yamaha yfm 200s the yellow bike runs great plug is nice and brown nothing worng with it the black one however runs like a bag of as* it Spitz out the carb it sputters runs real hot it's lean I know that but it literally has the identical carburetor every part of them is identical inside and out and no matter what I down I can't get it to richen out rather burn a whole lot of gas then burn the piston