Injector adjustment is critical for easy cold starting and power.
The rack lever adjustment is a learned art, more difficult with the old 2 screw levers, much easier with the newer 1 screw levers. Your reward for a careful rack lever adjustment is an old 2 cycle DD engine that idles smooth as an electric motor.
I still have one old DD 8V92 TI set at 440 hp that I crank up once in a while just to hear that sound.
Great old motors.