I believe its set up at the factory with consent speed governor, throttle position "idle" is 1000 rpm and "full" position is 1225 rpm. It is physically impossible to lower rpm using and adjusting the factory linkages. It has its original single disk pump with the fuel shut off cock. Using this fuel shut off (known in the truck manual as "emergency shut down") will lower rpm to 400 rpm then a shut off. The machine also has decompression lever setup.
This is what i do now, I use fuel valve to lower rpm to 500 rpm, at this point i decompress it holding the lever out and then i move the fuel valve back to full flow. I note white exhaust, this indicates raw fuel in the cylinders. Doing this i believe i'm leaving fuel in the disk pump not "running it dry". I always decompress and get it rolling when starting.
This ok with you guys who may know? Thanks 4 any help.