I have a 1975 135 hp Evinrude. There is a box I am trying to figure out what it is. The box does not show up on any of the parts diagrams. It is rectangular 2" by 3" box mounted by the cylinder heads. It has a part number of 511247 which doesn't return to anything. It has three wires: black ground, red plugs into the #3 terminal, and yellow that plugs into the #5 terminal. The red wire is fused. Any ideas what it is and what a good part number would be for it?
