Max output of 470 stator?

[nola mike]

Trying to troubleshoot something remotely for a guy with a 470. He says that he's getting 60v to his battery, doesn't know the problem. I haven't got any more info, but this seems like an awfully high output, even with a completely fried regulator. I had helped him after he took it to a shop, and they ran it without muffs :facepalm:
Certainly that could be the death blow to a 30 year old regulator, but didn't know if any further verification/troubleshooting was necessary, or if that 60v was plausible, and it's alternator time...

 

[GA_Boater]

An alternator puts out AC. If the rectifier diodes are shorted, AC is being applied to the regulator and it can't regulate AC to DC voltage.

So if the rectifier/regulator is shorted, AC would be applied to the battery. He is probably using a DC scale, tell him to switch the meter to AC. If it's working only a very small AC voltage will be measured. If it's a high AC voltage, the reg/rect is shorted. Check the output of the stator to see if the voltage is the same AC as he's seeing on the battery.

470 alternators/regulator/rectifiers are not cheap. I would go with an alternator kit that replaces the low power outboard charging system with a real charging system.

BTW - 470's have water cooled reg/rects - With no muffs, it probably got cooked. How is the impeller?

 

[Bt Doctur]

If you look at the regulator the copper pipe is just bolted to the back of it , very little cooling capacity that way.
Test the output of the yellow leads with a meter on AC . Depending on the rpm you may see 60 VAC output into the regulator, Next test the output on a DC scale

 

[nola mike]

Good points. Regardless of how he's doing it, and regardless of the failure mode of the regulator, I can't see anything else that would cause that voltage reading? I don't want to tell him to convert to an alt if there's potentially another culprit or easy fix.

So, they overheated his boat. They replaced the impeller. He goes out, it's running fine, he stops, it won't turn over. Gets towed in, and they told him he needed a starter. I told him to pull his plugs, then try to start. So water comes out of the cylinders. Had him check the flappers, which were of course fried from the overheat as well. They've charged him $3k so far for some suspect diagnoses that I helped him troubleshoot. Now he thinks I know what I'm talking about, and I don't want to disappoint...

 

[Bt Doctur]

nola, shoot me a pm