Murphy 6 cylinder in northwest 90

Can not move the oil over ride handle. What do we do? Will not fire? Help please

One or more of the 6 injectors are stuck.
Remove the small cover on top of the rocker cover.
Reach in and pull up on the finger pin .
Doing this takes the injector out of the rack.
Each time try pulling on the lever till you find which injector is sticking.
Once you have determined which injectors are stuck this injector must be removed, (with the injector tool)
taken apart and cleaned.
I have saved time and got lucky by laying the problem injector in a pan of heated ATF fluid, after about a hour most injectors will pop loose.
I do this when getting old machines started but, generally still have to remove and clean them.