Anyone else had the voltage regulator burn up on any Mercury motors? A friend of mine had his burn up just last weekend on his pontoon. A google on this shows this is pretty common. Apparently the tach will malfunction 1st-something to watch for. Also loose connections and weak battery may be suspect.

Thats pretty common in mercs. Normally you can find this by looking at the wires. The bullet connectors will be black and stuck together, or melted. Yea you can look at the tach. It will normally be jumpy, bouncing all over the place. Just replace. Normally takes bout 5 to 10 min.