Pretty sure I have figured it out.
Electronic governor control coil, magnet type. For genset of some sort, still trying to figure out what though. On application I know of is a rise in the excitation current being fed back into genhead from the power draw increases the currents in the coil bolted to the block which is more or less a magnet switch pulling back on the gov rod increasing fuel and air therefor speeding up the engine rpm. ''buzz box'' using external power.
Old school type. Some of the MSE engines had that, similar to air compressor idle kick down switch using air.
Edited by trowel, April 20, 2015 - 05:28 PM.