The "throttle cable" is attached to the governor speed control lever, and it has those two big springs that keep it in the idle position. The engine stop lever is the smaller one with no cable attached to it, just the air cylinder that pushes out to move it to the stop position - fully rotated clockwise until it stops. You can use a block of wood cunningly shaped to sit between the air cylinder push rod and the lever (just make it like a wedge and push it in until the lever stops moving, or I use a piece of mechanic's wire to pull it as far as it goes. If all you are doing is adjusting the valves and the timing, all putting the engine in no-fuel and idle does is make sure it doesn't kick or start by accident when you are barring it over to adjust each cylinder. It's not critical to the adjustments you are making. If you are going past that and running the rack, then several governor adjustments and positions become critical. It's good practice to lock the governor in no-fuel whenever you are working on the engine. Last year I had my engine out for around 10 months sitting on a stand, I wanted to test some modifications to the starter motor so put power to it to make sure it engaged to the flywheel properly. it spun the engine over (which is what I expected) what I didn't expect was at least several injectors still had a little fuel in them and it kicked for several revolutions. Scared the crap out of me because I had barred it over at least a dozen full revolutions while installing the new flexplate, transmission, etc -all with the engine in no-fuel - but I had taken the no-fuel lock off since I was in the final stages of rolling the engine back in. Should have left it on!
Brian