The "relay" on the far left is actually an electronic switch. I've got one sitting on my desk right now. I have never seen one of these available for sale.
This switch samples the RPM's of the engine from the sensor just below the starter, and when they hit 600 (or 800?? - don't remember which off hand), the starter shuts off and the field flash circuits are energized - that is the ONLY thing that this switch does - switch the starter off and turn on the field flash. It has a circuit board inside with around 20 components on it. One 8 pin chip, one field effect transistor, 3 diodes, one zener diode, 10 resistors, and 5 capacitors. All this is stowed in a case like the other relays.
The best part about this switch is that it isn't really necessary at all if one modified the electronics just a little.
If you are reasonably clever with electronics you could eliminate this part altogether by adding an additional momentary contact switch. That is what they did in the MEP831a generator. The mep-831a has a start switch that starts the unit. When the unit starts you let go of the switch as usual. At that point the unit is running but making NO electricity.
Then he would depress the momentary contact switch for 1 -2 seconds to flash the field and then release -- and the generator is making electricity.
I haven't laid that modification out in terms of exactly what pin on the switch goes where, but it wouldn't take more than a few minutes to figure it out. Just think in terms of making it like the 831a unit.
The only parts you would need to do this mod is another relay base -- you could take a relay like the other ones in the unit (easy to get - I've got 50 of 'em), open it up and strip out all the internal guts so that all you have left is the black base.
Some wire to make the normally closed connections on the relay base.
A momentary contact push button switch. (or a momentary contact toggle switch with a guard like the battle short switch might be better so that the switch doesn't get accidentally energized when the unit is already generating electricity)
Wire and crimp on connectors to patch from the relay socket ( the gray socket that the relay base would plug into) to the push button switch.
I haven't done the modification myself, but if I needed to (and right now I'm three switches short of need) I wouldn't hesitate to do it.
By the way, this switch is electronic, so it won't be clicking or making any noise at all.
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