60 hp mariner charging problem

amot69 · #1 August 15th, 2006, 09:33 PM

phatmanmike and jtexas i purchaced a new rectfier today (and tried to get a manual said it would take 3 days to a week go figure have part no book) well changed it and still same problem it wont read any higher than 12.86 but it will hold its own if you turn on lights it will stay at that voltage well at least for a half hour or so but its not puting out any more than that. i do know that the rectifier converts ac to dc but when testing the legs on the new rectifier i get 6.2 volts on the red to the batt 12.86 on one of the yellow from the reftifer and nothing on the the second yellow leg from the rectifier nothing in ac or dc i know that it showed continuity between the two legs , wondering if it could be the stator.did a visual check on all wires (even pulled flywheel) they all look good no weather check at all pulled plug on harness not a bit of corosion. i know the engine is older but it has very very little hours on it. i did order the book but any info now would be greatlly app

amot69 · #2 August 15th, 2006, 10:33 PM

bhile do you know the ohm reading for my 60 hp mariner s# a197683 i could check them and see if i have short or direct ground thanks

Texasmark · #3 August 16th, 2006, 03:49 AM

I may be wrong (probably not or there would be more wires) but I'm going to assume that the stator is single phase and it is isolated from ground. With that said, disconnect both yellow wires from everything and run the engine with them disconnected.

Take your AC voltmeter and measure between the leads and you should get an ac voltage reading over 13v which is rpm dependent. However, it may read zero till you get up to 1000ish rpm's. Some Merc stators are like that (9 amp for one).

If you get less than what I said then I'd suspect the stator.

Failure mode? If you have continuity between them (with the engine off) then you must have a short. A short could be caused by a deterioration of the insulation caused by age and vibration where the varnish wears off and the wires short. One shorted turn in a magnetic field of that sort can kill the whole thing. Guy named Maxwell figured it out a long time ago.

Mark