Poll - How are your Stator rewinds holding up?

[hp1000s]

OK...so having said that(LOL)...is it considered wise to eliminate the stator wiring loop that runs all the way to the left handlebar control-and back, if the headlight load will always be present? Oh yeah...tech-talk is kewl!

[SPARKSS]

If the headlight will always be on then you'll need that wire connected......so you could eliminate the "loop to the headlight switch". It'll likely shorten the life of the stator somewhat.......which is a marginal item working in a terrible environment at the best of times - they'll run for a heck of a long time but with no room for extra engine heat or electrical load - in my opinion.

[Matchless]

Here is quite an interesting take on the subject: http://www.shadowriders.org/faq/jumpstarting.html

Jump Starting – NOT from a Running Car

Submitted by Radford, B Davis

The issue is that cars (and 'wings and a very few other bikes) have a different type of alternator than our Shadows (and most other motorcycles) have.
Basic theory idea, for those who came in late: Generators of all types make electricity by moving a magnetic field relative to a coil of wire. The stronger the magnetic field and the faster it moves, the more electricity is generated. The moving part is usually called an armature or rotor. The stationary part is called a stator.
The typical car alternator is an excited field type. The magnetic field is created by an electromagnet in the rotor. Supply voltage is controlled by the amount of current going through the electromagnet. Most big AC generators are made this way. If an external power source is applied of a higher voltage than the regulator setpoint is applied to the system, the regulator will recognize the system voltage as being above setpoint and turn the field magnet (usually rotor) off. Result: No problem, as long as the applied voltage isn't so high as to damage anything (typically 25 V or higher on a 12V system). So you can (usually) jump start a car with another car, or a GoldWing without any problems.
Now the bad news:
Most motorcycles don't use an electromagnet to create the magnetic field. Instead ,we have a drum-shaped rotor (usually on the crankshaft) with several permanent magnets placed inside (a magneto). These magnets moving past the stator coils create the electricity we need to run the lights, charge the battery, etc. But you can't change the strength of a permanent magnet. So regulating the generator output is not a straightforward issue of turning the field magnet strength up or down.
The motorcycle voltage regulators I've seen all take the approach of shunting excess generated power to ground. This has the advantage of making sure that the voltage is the same everywhere in the system, but the disadvantage of meaning that the stator is always flowing its maximum rated supply current. This, I think, is why many motorcycles have a reputation for frying stators.
So the design of one of these regulators is completely different from a cage regulator. It has a voltage detection part, like the other regulators, but the big resistor/power transistor package has to be strong enough to carry all the possible excess power generation to ground. It handles a lot more power than the car regulator has to. It generates a lot of heat as it does this, which is why the regulator on my '85 VT1100 is finned and out in the open air--to carry off the heat before it cooks something in or around the regulator. A typical bike magneto makes 30-50 amps at max power. So the regulator is designed to dissipate a maximum of about 700 watts for short periods (this would be full power and no loads on the bike--the battery and lights are all missing). In practice, this cooks the regulator pretty fast--they don't like to dissipate more than about 200 watts for any length of time.
Now consider what happens when your moto regulator is doing a good job keeping the system at a nominal 14.1 volts when running, but the battery is weak, so you have to jump-start it on cold mornings. You hook up the bike to your Toyota with a 95 amp alternator (max output about 1400 watts). The Toyota's voltage regulator keeps *its* system at a cozy 14.3 volts when the engine is running. We now have a problem.
The cage's alternator and regulator want to maintain the system at 14.3 volts. Your bike's regulator, the instant the system is turned on, is going to try to bleed off excess voltage from the system to keep it at 14.1 volts. The car's alternator is rated for 1400 watts. The bike's regulator can dissipate a maximum of 700 for (very) short periods before it cooks itself. It's a tug of war, and the bike regulator ALWAYS loses.
Moral of the story--jump-start your bike from a non-running cage. The quiescent voltage of a car (or bike) battery is in the 13.2-13.8 volt range. The only result of this is that the full output of the bike's magneto will go into the cage and moto batteries once the bike starts. This actually reduces the load on the regulator to near zero, so it's quite happy with this state of affairs.
Corrolary: Want to reduce the load on your bike's voltage regulator? Install MORE (or brighter) lights. No kidding. Since the regulator only handles power output beyond the bike's demands, installing more demands means that the regulator does less (and is happier). The stator does the same amount of work in either case, so no problem there. Be forewarned, though, that Honda didn't exactly break the bank on copper for the wire in our bikes. It's sized to work just right with no corroded connectors and the stock loads. You need to run larger/more supply wires from the battery if you intend to use significantly more power than does the stock system.

[Matchless]

My stator was rewound by an old hand in the trade who told me that he used the specs from a newer model as the OEM stator was very prone to failing on the 1980 GS bikes. He used heavier gauge wire and definitely fewer turns, which gives out about 40 volts AC per phase instead of the 70 - 90 volts quoted by some people. I recall not seeing any voltage change on the battery above about 2000 rpm, voltage stays just under 14 volts on a full battery, nothing changes when lights are switched on and off. My 3rd winding is permanently connected. I have not noticed any charging problems and drive with lights on in town a lot.
I recall my old beach buggy days and the only good test on those old 6 volt bugs was to wire an ammeter to the battery and see if the charge with and without load is positive and that a low current flow goes to the battery when full and higher when discharged and that it does not show any negative flow except maybe when idling.
I should do a quick check of this on my GS.

[SPARKSS]

[QUOTE=Matchless;738437]My stator was rewound by an old hand in the trade who told me that he used the specs from a newer model as the OEM stator was very prone to failing on the 1980 GS bikes. He used heavier gauge wire and definitely fewer turns, which gives out about 40 volts AC per phase instead of the 70 - 90 volts quoted by some people. /QUOTE]

Hi there Matchless.......Your "old hand" understands the problem exactly.

[hp1000s]

Sparkss
Thanks much for the reply, but I guess I wasn't really accurate in asking my question. On some of our GS', the lighting stator phase/coil(whichever: one of the three yellow wires from the stator) runs all the way to the light-switch on the left handlebar, so that it could be potentially be switched on/off when the 12V side of the headlight switch was turned on/off (my understanding was to eliminate some of these stator stress problems). However, my bike, like alot of them, have the headlight switch rigged "permanently on(along with that yellow stator wire circuit)", by Suzuki....so, since my headlight will be permanently on, I'm assuming that I don't need to run that yellow stator wire circuit all the way to the left-side control(with all of it's associated xtra wire), since the headlight switch is never going to switch off either the 12V to the bulb or disconnect the yellow AC wire. I'm not wanting to eliminate that (stator) circuit, I just want to eliminate all that xtra wire that's not serving a practical function. Hope I've done a better job of explaining myself.

[Matchless]

[quote=SPARKSS;738506]

My stator was rewound by an old hand in the trade who told me that he used the specs from a newer model as the OEM stator was very prone to failing on the 1980 GS bikes. He used heavier gauge wire and definitely fewer turns, which gives out about 40 volts AC per phase instead of the 70 - 90 volts quoted by some people. /QUOTE]

Hi there Matchless.......Your "old hand" understands the problem exactly.

SPARKSS,
Interesting topic you have here as there are opinions, thoughts and views that differ quite a lot if you start googling this and some are given for fact and can be very confusing so anyone who does not have an in-depth insight into electrical/electronic theory and functions.
Just for interest my GS had the switch part bypassed in the headlamp and the two wires were just plugged into one another. This is also shown to be so on the wiring diagram and was one of the first mistakes, as this wire caused problems as the connector sheath shows some overheating. I just bypassed it by plugging 3rd phase directly into the wire from the regulator.

My personal view is also this, the electronic components used 28 years ago were not always "over engineered" as using very high voltage SCR's, zeners and diodes in those days were very expensive and in some cases not as readily available as today. Components nowadays are most probably more robust and it is easier to find a component that may even have double the current and voltage handling and I think not much more expensive, so that may also have been a contributing factor. The fact that the 3rd phase was not regulated may also have contributed and then the thinner wire on the stator. So there were quite a few things that were not too robust.
These things only started giving problems if something went wrong or if an owner started fiddeling with the electricals or if a bad battery was not quickly replaced, corroded connections, jump starting from another running vehicle etc.
I still have the original regulator fitted in 1980 and it is still working fine after 28 years, so the design was not really much flawed for the time, it just did not have many safeguarding features and these were only picked up over a period of ownership. More robust components with a bigger safety margin and Suzuki would not have become known for electrical/charging problems in that era.
My view and thoughts only.

[fgh]

Any idea why it fried?

The black stuff on the metal core was chipped off in a few places. Since it was grounded I think the edge wore/burnt through the insulation on the magnet wire.

[hp1000s]

Thanks, Matchless!

[srsupertrap]

RE: tfb remark "Suzuki wiring arrangement"

Agreed, I have read the same statement. I filied down the headlight switch long ago so I could turn the lights On & Off in the belief I would extend the life of the entire charging system. After my first stator failure back in 1983, I installed a VDO voltmeter between the speedo & tach with the leads hooked up directly to the battery.

My observation is the VDO voltmeter actually reads higher with the lights off than with the lights on which is somewhat counter intuitive considering the third phase is engaged.

[posplayr]

I'm now convinced to change out my Stator

as well as the Regulator. I'm hoping the ElectroSport is redesigned to reduce the output power for a given RPM.

Thanks for the discussion in this thread. I posted earlier the same fact that the motorcycle power generation is markedy different to most cars. The power output of the stator(with permanent magnets) is essentially proportional to engine speed. At zero RPM the battery kicks in to provide power where there is none from the stator. At high RPM theover the top at high RPM .

http://www.thegsresources.com/_forum/showthread.php?t=118210

Pos 8)