Evinrude Tachometer Not Working Properly

Hi guys, the tachometer on my 96' 115 Ocean pro is doing some crazy things. The old tach was giving me random readings and the pointer was broken off so, I bought a new Faria tach. I nstalled the new tach (the engine has the modular wiring for the tach) and I am getting the same results. It seems to work fine until around 4000 rpm then it drops to zero and stays there until I bring it back to idle. Some times it goes to 3000 and drops off. Where do I need to begin to identify the problem. Thanks in advance.

You should begin testing the regulator/recitfier and the output from the two yellow wires from stator. Usually this fault is regulator recifier. You could put a Voltmeter on battery and monitor battery voltage. When the tacho drops off, look for the battery voltage. You probably find its going from charging (around 14 volts) back to battery voltage.

If you have a DVA meter you can easily measure output from the stator.

Had the same exact issue on my 92'115. It was the regulator/rectifier. The guy that i get my parts from said something about them catching on fire sometimes when they go bad (its been a few years, i don't remember exactly). Point is change it soon.

Thanks for the help guys. I will look into that as soon as I get off work.