Mercury 200 2 stroke tach issue (reading high)

[ctak]

I have a 92 stroke mercury 200 and I took the boat out for a spin over the weekend. I noticed the tach was reading high. I would run the throttle to about half but the tach was reading 5500.. I'm sure I was only running around 3K. Also I noticed the voltage output was only around 13.4, I think it usually runs around 14.4. I was wondering if one of my power packs is bad or something else is going on.

 

[Texasmark]

Most engines count rectified [in the rectifier regulator module(s)] signals from the alternator for tach drive. I think you are on the right track. No experience with dual regulators on outboards....aka how are they wired, what kind of outputs to sum and feed a single load without feedback from one effecting the other. Assume the tach (grey wire on my last Merc) drive comes off just one of them. That should give you a clue as to which to check first......if they are the same part number, just swap connectors and see if the problem follows the module.