OutdoorKing Repair Forum Forums Collectors Corner Ride On 11 HP B&S

Does anybody know what A/C volts I should be getting from the stator on one of these motors?

Hi Norm,

I have an older (Dec 1980) B&S manual...it shows multiple types of alternator. Regulated, unregulated, AC, DC, AC +DC, and combinations thereof.

22 pages on alternators alone, and that's pre-1981!

Do you have an idea what the alternator does? Just run lights, or charge battery, or both?

No actual voltage is really listed, but if it is the AC lights-only type it says a test lamp should achieve 'full brightness' at medium speeds on thendual circuit (lighting and charging) type.

Lighting only AC type is probably 8V at 2400rpm and 12V at 3600rpm for 70W load. Load lamps should be a sealed beam unit. Now the older American car ones were 12V 37.5W I think but may be 55 to 60W by then. It says load should be 60-100W, which makes sense for 2 x 37.5 headlamps = 75W. This is a 5A alternator. So says the manual.

Otherwise I will guess the unregulated stator output under a load should be roughly 12-14V multiplied by the square root of 2 to take account of the AC factor. I think! So expect somewhere in the 12-18VAC range I think. 12V system.

What exact issue are you trying to solve, I may be able to help from the manual further?

Good evening Norm,
I have this .pdf saved on Alternator Specifications, and here is the link from the B&S website:-

https://www.briggsandstratton.com/~/media/Files/FAQs/BriggsAndStratton/PDFs/alternator_specifications.pdf

And this seems to be an updated version of the B&S Alternator Replacement Guide I have: -

http://www.briggsandstratton.com/~/media/Files/FAQs/BriggsAndStratton/PDFs/alternator_replacement.pdf

Both may be valuable resource for your current and future needs.
Hope these help.
Daryl

Hi Norm,
Sorry for the additional message, but do you have the Engine information to confirm the Alternator installed? Using the Illustrated Parts List should help identify the alternator for your specific engine, then you can check the above Manuals for details on the Alternator you have.

As an additional resource, here's a link to the B&S FAQ on their Charging System Test to go with the .pdf files above:-

http://www.briggsandstratton.com/us/en/support/faqs/charging-system-alternator-test
Regards
Daryl.

Thanks Patrick, I just want to charge the battery, the lights I can run D/C. Wiring loom has been all tampered with previously.
Daryl, I'll have a read up on the info you linked up, bit busy today have to pick the Duetcher up and once I get home with that it will be like a new toy so that will wipe out the rest of the day

Daryl I tried reading my way through the link but the don't make it simple, I just did an A/C check across the 2 wires from the stator and I'm getting about 4.5 volts A/C so I assume the stator is toast, Anybody know if the stator from a 12.5 might fit before I buy the motor

Could be the magnet is toast... was one thing it said to check in the manual (not at home at the mo) as a weak magnet will mean it won't generate the appropriate current/power.

Could be Patrick, that is something we were discussing last night at our club meeting and that was to make a unit to re-magnetize old Enfield rotors. One bloke has the information as to how to build one. Not sure but the fact it produces some power may indicate something. I think there are 12 magnets running around the outside of the stator and they all seem to have about the same magnetism as the ignition coil magnet

Good evening Norm,
Do you have the Engine information (Model & Type) to confirm the Alternator installed?
If so, I can use the Illustrated Parts List to identify the alternator for your specific engine, then check the above Manuals for details on the Alternator you have.
May then be able to check if this particular Alternator was used in any other engines.
Regards
Daryl

Sounds like Daryl's got a more useful info / offer of assistance again...

Only other thing are you sure the stator should be putting out AC- it may have an integral regulator (some did)? Maybe check the DC output as well.

I have sent the info I have on it to Bruce, what I am not sure of is the info in the parts book. There is 3 types a dual circuit ( I assume this is an A/C D/C type), then there is a tri circuit? don't know what that means and then the third is just listed as a 10 amp In the pics they all look the same. Patrick I can't see anything on this stator that looks like it might be a rectifier to convert it back to D/C

Just checking this stator because it is bugging me, I am getting about .8 ohms from the black wire to the frame, zero from the red wire to frame or between red and black so I am thinking this stator may be ok? Anybody have any thoughts on this ?

Hi Norm,

Just a clarification: I assume zero (Ohms) actually means zero (short circuit or near enough), and not "no reading" or "or" (overrange) or "----" which indicates infinity (open circuit).



and



Dual circuit means AC and DC: Ac for running the lights, DC to charge the battery.

One system has a rectifier (diode) in the plug. There are two wires out of the stator: red for charging the battery through rectification to DC (actually likely just rectified AC) and black for AC running the lights. Return in both is through the chassis/engine block/ground. Just to emphasise: red and black do NOT mean +ve and -ve in this case!

The stator resistances should be measured across the following, deviations indicate a faulty stator:
- red and stator laminations with ground wires connected: continuity (low or zero Ohms)
- red and stator laminations with ground wires disconnected: infinity (open circuit).
- black and stator laminations with ground wires connected: continuity (low or zero Ohms)
- black and stator laminations with ground wires disconnected: infinity (open circuit).

A second system has a fuse with a solid state rectifier for charging. There are two separate wires (unknown colour) with differing plugs. The DC charging wire has a fuse.

The resistances should be measured across the following, deviations indicate a fault:
- fuse and red connector- continuity (low or zero Ohms), this is actually the charging wire
- don't forget to check the fuse too.

The stator resistances should be measured across the following, deviations indicate a faulty stator:
- two pins in connector: continuity (low or zero Ohms).
- each pin in connector and ground: infinity (open circuit)

Haven't gone into tri-circuit or 10 amp as it's getting late. Tri-circuit has two diodes for rectification, one charges the battery + other loads whilst the other rectifies for the lights. Some of the other alternators also have 4-pin connectors, and solid state regulators. Haven't gone into them here either.

Hope this helps,

Thanks Patrick, you seem to know your way around this stuff. I cut the plug off so I could remove the wire from behind the starter motor and I remember it did look a bit bulky so it could have a diode in the back of it, it had been repaired with heatshrink at some stage.I will strip it back and have a look at it. The red wire just went straight to the battery, the black wire went to a funny looking round thing which could be a regulator for the A/C but it has no fining on it so I doubt it is.I will check what I get out of Red to ground and black to ground. All the wiring loon had been repaired in a sort of rough fashion so I have to stumble my way through what had been connected to what Thanks for your help

Hi Norm,

Re: knowledge, You're too kind...all I can really say at the moment is: So says the manual!

At this point it might be better to wire your own. The wiring for an alternator appears very simple, a matter of a few simple connections. In fact you might be better doing that and wiring in your own rectifier/regulator from, well, almost anything as a proper rectifier will give you full-wave rectification as opposed to a simple diode give �-wave rectification. Double diode may provide full-wave rectification, but without the smoothing. Rectifier/regulator may also give you a proper voltage for charging, prolonging the battery's life rather than the AC current likely directed at the battery. In this case you can't use a modern car's regulator 'cos it uses feedback to vary power to the actuator coils in an alternator, and we have fixed strength magnets rotating.

All easy to work out with a multimeter using AC/DC settings.

Full wave may also give you a more efficient output, but it could possibly also therefore increase the power consumption, and importantly heat generation in the coils. But then again, it may do the reverse and reduce power dissipation (due to the �-wave rejection cycle) I suppose.

Or it may not work at all. All could be, maybe, possibly- what fun, good luck!

Let me know if you have any more questions though and I'll try to help.

Thanks Patrick I was way ahead on this one and I fitted a rec/reg from an Enfield right at the start but that didn't sort it out. The startor looks fine, nothing appears wrong, and yesterday I did get a spike of 19 volts A/C but the rest of the time it hovers at around the 8/9 volts A/C. I know I'm being fussy with it but if it is supposed to work I would like it to work. It is only for starting and it fires instantly on the starter so it draws very little. I guess if I mounted a solar panel on the bonnet that would be enough to top the battery up but I don't think Jack would be impressed.

Hi Patrick, how about this for an idea, no need for an alternator then.
http://www.ebay.com.au/itm/12000mAh-Car-Jump-Starter-Booster-LED-Charger-Pack-Battery-Power-Bank-3-USB-/191839616474?hash=item2caa883dda:g:HvMAAOSwZ8ZW4n5C

This way I could probably get away without even a battery, just this little pack mounted where the battery would go.It is only needed for cranking the motor and should also be able to power the 2 LED headlights if they were ever needed. Sounds like a win win to me, any thoughts or ideas?
If this idea works I will do the same on the Duetscher, the stator on the Honda on that doesn't appear to be charging either

Hi Norm,

Have a similar one of those already. Yes it will jump start a car repeatedly (tried on 4-cyl 1.8l, ~3-5 starts and only 20-40% capacity used, they claim will do V8s/smaller diesels but untried).

Bought from Costco, brand Powerall. Here is an example. You also get an in-built torchlight (which should easily run 24+ hrs) PLUS USB outputs (and phone connectors) so you can charge phones repeatedly too. And in a carry case. It now sits in my car.

Youtube the Americans who do jumpstart V8s with them.

They have Li-ion batteries and hold a substantial amount of power and can deliver it *quickly*. How many other things that small do you know can supply 200+Amps to jump start a car (would a lead-acid battery that small jump start a car...and what happens if you short its terminals)?! I wouldn't want to get on the wrong side of one misbehaving because it's been misused!

As a result get a good, name brand, reputable one or youll end up with *cheap* *#$%ese batteries with a ridiculous 250,000,000MAh rating and a device not rated to Oz standards and could end up homeless like those cheap "hoverboards" which will (I guess) be using similar batteries. (Rant off now)

So, a few caveats about mine:
- They are designed for jumpstarting
- They are not designed for continuous drain through the 12V output
- They are not designed for charging through their 12V output.
- I have heard tell of extended cranking causing the connections/solder to melt...look at the wire+connector thickness and imagine 200+Amps... Use gloves! Mine did get slightly warm even with a quick start.

But having said that: they are very, very useful and can make the NRMA redundant for probably half their calls (I guess)!

Mine maintains charge for months. I 'top it up' occasionally, every 2-3 months or so.

Mine will recharge from either 240V or 12V (both plugs supplied).

If you want a photo of my kit I can send you one when I get home this evening. Otherwise, ebay my model is (I think ) PowerAll Deluxe Portable Jump Starter/Power Bank/Flashlight PowerAll PBJS12000R but make sure you get a 240V Oz-plug charging adaptor. They also were available from motorcyccle shops, a few in Repco once, etc. Found Costco the cheapest bricks&mortar retailer.

Although it claims an output of 12V/10A I haven't seen it in the manual although it's in the specs so it's a bit unclear. I would assume it'd be OK for a couple of Amps or so. Continuous drain may cause heat problems.


I think your 12V w/ a solar charger is actually a very good suggestion and when I was a member of a gliding club 10-15 years ago that's how owners all maintained their long-term-stored batteries. Just get a good regulator so you don't overcharge the battery or reverse discharge overnight.

Cheers,

One other thing of course was: any chance of
- trying another flywheel/magnets on the 11hp B&S
- trying the suspect stator on another known working system?

Thanks Patrick, good points you made there so I guess the next thing would be one of these, they have been around for quite a few years now and still way cheaper than a new battery, new stator and a new rec/reg and you can pump the tyres up as well. What could possibly go wrong with this idea?. I don't have any other B&S motors here at the moment, the others are Hondas

http://www.ebay.com.au/itm/262345097832?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT