I have received a tach as a fathers day gift but it has no instructions with it. There are four wires black, green,white, and red. I am pretty sure that the black is ground, the red is for the backlite, and am not sure what the others are for... I want to connect with a stock 235, and if you take the cup off there are a couple of loops of wire inside. My memory tells me that 40 years ago one of these loops had to be snipped. No brand name on the tach, but is has a couple of mooneyes on the face.... Help!
