TomC said - If comes down to it, you could remove the start/stop solenoid from the governor-then it will be in the on position. Then just jump the starter to get it running. Once done, manually press on the stop lever on the governor to stop it. Personally, I would tie a small rope to the governor, so you don't get caught up in the spinning radiator fan drive shafts. You need very little to fire it up and move it. Good Luck, TomC
I'm trying to attch a couple pics to help identify the start/stop solenoid. Is it the long things that screws into the side with the 3 wires or it it the shinny brass air valve?
If I'm looking at your picture right, the shiny brass valve with the 90 degree single air line should be it. You may be able to remove one of the mounting screws, loosen the other and just swing it out of position.
To be sure, put the bus in neutral, block it or do whatever will keep it in place safley (!), and jump start it. Once pressure gets high enough, you can watch the correct valve push the govenor arm and shut down the engine. Then swing it out of the way with the engine off.