Charging 85 hp 1972–upgrade stator?

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    amuller

    US Member - 2 Years
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    #180318

    I am sort of unclear whether to post this here or in the tech section, but there seems to be more traffic here. Opinions?

    OK to the subject: The flywheel alternator on this motor is rated, apparently, at 9 amps. There is an upgrade kit which is rated at either 15 amps or 12 amps depending on where you look.

    The motor does not seem to charge much, though I have checked out the stator and replaced the rectifier. Is it worthwhile to upgrade to the higher output stator?

    OMC apparently sold a kit including a regulator and an ammeter, but the stator itself is cheap.

    Is there an easy way to tell which stator is which?

    Thanks.

    frankr
    frankr

    US Member - 1 Year
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    #180319

    I guess you must be needing more charging or you wouldn’t be asking. Just wondering though, why?

    • This reply was modified 8 months, 1 week ago by frankrfrankr.
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    fleetwin

    US Member - 2 Years
    Replies: 2940
    Topics: 38
    #180331

    Me too, don’t ever recall having an issue with the battery CD charging systems…
    Have you put an ammeter inline to check the actual output?
    Keep in mind that there are two other items that tie into the alternator output that could have an effect…
    The shift diodes….These diodes AKA “monkey balls” are tied into the stator to supply current to the shift solenoids so the engine will stay in neutral when the key switch is turned off and the flywheel is still spinning…A quick test is to shut the engine off while at high idle in neutral…If it slams into forward gear before shutting off, there is a problem with the shift diodes…
    This engine also has what is called the “clipper circuit”, which is really just a basic regulator…The clipper circuit kills half the alternator output if it senses high voltage, such as a loose/corroded battery connection…So, if this unit is messed up, you will only get half of the alternator output…But, keep in mind, the clipper might actually be doing its job because it is sensing high voltage!

    Again, I never encountered an issue with these 9amp systems not keeping up with basic electrical needs, so I would check the items I have mentioned before investing in an expensive larger output stator…Would love to see any info you have on this kit, don’t remember anything like that being offered…

    frankr
    frankr

    US Member - 1 Year
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    frankr
    frankr

    US Member - 1 Year
    Replies: 4823
    Topics: 48
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    fleetwin

    US Member - 2 Years
    Replies: 2940
    Topics: 38
    #180344

    I’ll be darned….Wonder why the rectifier is included, couldn’t the old one be reused? Wonder if the original clipper circuit is still used in conjunction with that regulator? Very interesting…

    frankr
    frankr

    US Member - 1 Year
    Replies: 4823
    Topics: 48
    #180345

    Not sure about the rectifier, but I assume the original one can’t stand the amperage. Also can’t answer the clipper question—don’t know.

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    amuller

    US Member - 2 Years
    Replies: 896
    Topics: 142
    #180347

    Yes, that’s the kit I was looking at. And the stator is only $20, so I might order one. There are various rectifier numbers, with varying numbers of leads and some claiming to be “regulated” and some not. Sometimes there is a separate regulator, sometimes not. Is the kit intended to be used with a rectifier, a clipper, and a regulator? Hard to tell without the instruction sheet for the kit. Some sources recommend removing the clipper as doing more harm than good…. Then there is the advice to NOT use sealed batteries, which are pretty much the only type readily available these days. This kind of makes sense when the charging source is unregulated, as water will be boiled out of the battery and not readily replaced.

    frankr
    frankr

    US Member - 1 Year
    Replies: 4823
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    #180348

    As I understand it, (some) of the aftermarket amplifiers have built-in overvoltage protection so they say the clipper is not needed for those. That’s all I know. Been too many years since I got away from them. Or maybe not enough years?

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    fleetwin

    US Member - 2 Years
    Replies: 2940
    Topics: 38
    #180391

    Keep us informed if you purchase this kit….Will be interested in the contents, and the instructions!

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    fleetwin

    US Member - 2 Years
    Replies: 2940
    Topics: 38
    #180392

    Yes, that’s the kit I was looking at. And the stator is only $20, so I might order one. There are various rectifier numbers, with varying numbers of leads and some claiming to be “regulated” and some not. Sometimes there is a separate regulator, sometimes not. Is the kit intended to be used with a rectifier, a clipper, and a regulator? Hard to tell without the instruction sheet for the kit. Some sources recommend removing the clipper as doing more harm than good…. Then there is the advice to NOT use sealed batteries, which are pretty much the only type readily available these days. This kind of makes sense when the charging source is unregulated, as water will be boiled out of the battery and not readily replaced.

    Well, in this case, if using the “kit”, the clipper and the regulator seem “redundant”, so I would be shocked if the instructions did not advise removing the clipper. But, keep in mind, that this kit is old, and so are the instructions. The regulator in the kit does the job of the “clipper”, which is really only a simple regulator….
    And yes, would definitely use a refillable battery. There won’t be much draw on this higher output system, and the “regulator” will only cut the output in half….I would probably install a voltmeter in the dash….I would skip the ammeter because the wiring is so messy….You have to disconnect the rectifier output lead, then run a lead up to the ammeter, along with another lead coming back to the engine/battery…Messy, and problematic…

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    amuller

    US Member - 2 Years
    Replies: 896
    Topics: 142
    #180405

    As far as I know marineengine has some of the pieces but isn’t offering the whole kit.

    Wiring a direct reading ammeter would be a pain but wiring in a shunt isn’t such a big deal. But of course then you have to decide where to put it. Do you want to know the alternator output, or the net charge into and out of the battery…..? I’m for the most part satisfied with a good voltmeter. Easier to install and gives a direct warning of overvoltage, in which case turn on some loads.

    By the way, I picked up a (free!) ’72 100 hp parts motor (quite likely could be a runner) and I see it has a breakerless ignition. Of course it uses a different CD box–one even more expensive–but does anybody know if the breakerless ignition can be installed on a point-ignition motor? And how it compares in reliability?

    frankr
    frankr

    US Member - 1 Year
    Replies: 4823
    Topics: 48
    #180407

    Pretty sure it would have a different crankshaft, cam for points, vs key for notched timer rotor. But I haven’t actually looked it up.

    OK, Motorola Amplifier (breaker points) vs Prestolite (breakerless) Pulse Pack. They are pretty similar in the way they work, except for the triggering method. Both systems use that POS distributor cap. The Prestolite had a nasty habit of suddenly stopping dead in the middle of nowhere and working just fine by the time you got it towed in. I found it hard to like for that reason. On the other hand the Motorola system had the points. I don’t see that as a big problem because the distributor required maintenance service anyway. The points themselves never burn and pit their contacts like “regular” breaker points. But with many hours running they wear mechanically just from opening and closing a few million times.

    So it is mostly a matter of choice and opinion. My personal choice would be the Motorola. Matter of fact I had a new one on my own boat back in “The Day”, and it never gave a bit of trouble.

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    amuller

    US Member - 2 Years
    Replies: 896
    Topics: 142
    #180422

    Thanks, frank. This motor isn’t idling properly–it sneezes and revs up and down. I have no evidence but my gut feeling is that it’s the POS distributor. I looked for carbon tracks and other obvious stuff when I had it open and didn’t see anything. I can try to localize it to a cylinder, but aside from that, what should I look for?

    This ignition kinda seems like the worst of all words–potentially troublesome and expensive CD box, and POS mechanical distributor. I like the old 4 cylinder West Bend ignition: four point sets, mounted at 90 degrees, each firing it’s own coil. No electronics. No distributor. I suspect if I got motivated I could gin one up.

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    amuller

    US Member - 2 Years
    Replies: 896
    Topics: 142
    #182761

    I spent a few minutes comparing part numbers on marineengine.com. *IF* they are correct (as they generally are) the crank, crankcase, flywheel, charging stator, etc are the same. Only the timer base and the electricals are different. Plus the triggering rotor of course. So it *should* be possible to swap the systems.

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