Showing my stupid here, but what are those 2 units with the wires attached on the front of the Grasshopper?
About that neighbor..............You need to do your part as a good neighbor yourself. Get rid of the cheesy little tube mufflers on the header pipes, and put on some real mufflers that will keep those motors quiet.
Performance upgrades like free-flow exhaust and intake aren't much good without bigger main jets, and if you have those things they should be for the track or the wilderness. Be a good neighbor to your neighbor and to the cops he keeps calling, quieten those motors down.