Manual shop (repair manual) for 1983, GE280

If, I understand you correctly, you want the air/fuel mixture screw for the Injector body of your vehicle, but you have lost me at the, " the manual shop" bit; I do not follow that part.

Cheers,

Essentially, you will need a Co2 meter to adjust the fuel air mixture.  The settings are between 0.5% - 1.5%.  Best, aim for a 1% setting.

But from a rebuild situation, in principle the adjusting screw needs to be at half way.  That is going to be difficult to judge, as you are not going to know from threading in the screw, at what point it will start touching the adjusting pivot, therefore, I suggest you carefully and slowly wind the screw until, it bottoms out.

When it has bottomed out, unwind about 6 full turns.  Starting the engine is going to be a trial and error affair from hereon, in.  When the engine has started up, the only way is to set it by the meter, you can not adjust these engine as an experienced carburetor mechanic could do.

Cheers,