Second Kill Switch??

[Haironyourchest]

I mounted a new M-Tronic carb on my Stihl FS460 c-em brushcutter, but there is a white plastic dangly thing with red and black wires coming out of it that cannot be connected to the new carb. The old carb had a recess and threaded hole where this thing was supposed to go, and the end of the choke lever mated with it as well. From messing around, I take it to be a secondary kill switch, activated by turning the choke. Does this sound familiar to anyone? The brushcutter runs without it, but it's revving faster than before, putting out over10 thousand rpm with the strimmer head at no load - manual says should be 8'500. With the blade it's hitting 11 thousand. Any thoughts?

[Haironyourchest]

The first pic shows the old carb and how it mated with the dangler. The second is the new carb, installed, with the dangler dangling.