Re: Voltage reading from a '77 'rude 55hp 2cyl2st WOT
If your battery died on you, then something is way wrong. It should never get down to 12 volts, much less below 12.
Unless maybe you're running a trolling motor on the cranking battery? Or one a those fancy oxygenated bait tanks? Or a huge amp to blast your tunes out over the water?
The FF won't hardly draw enough current to measure, unless it's also a GPS having a hard time locating a satellite.
unregulated charging voltages usually get on up there, 15, 16 or more volts. A high quality marine led-acid battery will handle it. I been using Interstate deepcyles for cranking -- total of 11 years from the last two.
An AGM or gel-cell battery won't tolerate that much charging voltage very well.
If the voltage is higher when the motor's running, then it's charging but it does sound like not enough.
Corrosion/loose connections will drop voltage, so inspect all the wiring coming into and out of the rectifier. Measure voltage at each junction in the circuit from rectifier to battery to rule out a wiring problem.
And as said, get the battery load tested.....a failing battery will drag the voltage down, too.
