Mercury 75 hp. Question about adding a voltage regulator

I'm going to add a voltage regulator to my older motor, made in 1986. It's got a rectifier, no regulator. I'm having issues with my fishfinder and other electronics registering high voltages, shutting off, etc.

CDI seems to be a favorite maker of these things, but Amazon carries some regulators in the $26-$35 range that replace the CDI part 194-5279 (which runs $85-$110 depending on where)

This one, for example: https://www.amazon.com/Regulator-81...8&qid=1509282337&sr=8-3&keywords=cdi+194-5279

And this one: https://www.amazon.com/gp/product/B...title_srh_1?ie=UTF8&psc=1&smid=A3B3W8LFSNVNUV

Anyone have experience with these less expensive voltage regulators? Amazon customer reviews are mostly very good, especially for the second one cited above.

You will get what you pay for.

My advise: Buy the CDI unit. I've installed several other regulators and they drove my tach nuts. The CDI unit has a separate (grey) wire to run the tach, and it works.

Jeff

I would stay with the rectifier and get a good old fashioned deep cycle lead acid battery. The battery's internal resistance works as a regulator.

I have a '86 - 60 hp with a rectifier, with the motor idling I have about 13.5 volts and at WOT I have about 14.7 volts, well within the range of operation of most sonar units.

If you are experiencing interference, the regulator is not going to fix that. The battery fills in the gaps in the wave form and there is a small AC ripple on top of the DC. The sonor electronics filters it out.