Hey guys weird question

I have twin 225 evinrudes 1998’s. When they are running the starboard engine will not display rpms through the tach designated to that motor instead it does it through the port side tach. Along with that the port side motor still displays its own rpms through the port side tach. I’m afraid that I will be causing damage to the rectifier if I have two that are working against each other. With that being said it makes no sense that they would display through the same tach. They aren’t even hooked up together! Any ideas? These are analog tachs by the way.

I have replaced the stator the rectifier... soldered in a new ground for the ignition module also replaced the body harness running from the console to the motor and just last night installed a new ignition switch... stator blew up and took out a lot of parts with it. Maybe it took the tach out with it as well. Not sure what brand of tach it is but I know that it’s plug and play with the 1998 evinrude ocean pro. Even if it took out the tach with it why would the known good tach be getting a reading from a motor that’s not even hooked up to it? I can fire either one of those motors and get a reading on just the one tach. To be honest it scares me thinking that I have two rectifiers working against each other. I’m pretty sure it can’t be a good situation