Riders Of Vision

I happened to mention at work how there was at least one case I had read where a stator fried itself with almost predictable monotony..........

"I know what causes that, you need to change the flywheel." was the comment.

He had a case years ago on an XZ550 with the same symptoms.  It turns out the polarity in a couple of the magnets was back to front instead of NSNSNS etc it was like NSNNSSNS, loaded up the windings something terrible. Changing the flywheel solved problem.
He quoted some other cases on different bikes with essentially the same problem.

Hope it helps someone.

Interesting I wonder if one could test this with a small neodymim magnet marked with an N and S. Then as you moved it around the flywheel it would point SNSNSN and if it was bad it would be SNSSNNSN

Yup that's how they tested, violent reaction when it came to the double.

If true, that would explain the randomness of the failures.

Hmm, who do we know that could test this out...  I think I heard of someone who went through stators really fast....  He might even have a compass or something  ;D

Brian

He's too busy star gazing :P

I've changed the R/R (again) and have more than the usual miles on this stator - still going strong.  Or at least it was when I parked it last Fall.

I have wondered about the flywheel in the past - but more as a source of vibration than magnet issues.  If the current stator fries soon (mileage-wise) I'll try a swap.

Thanks for the info!

Yes, I have been spending lots of time both looking skyward and now getting ready to build my next telescope.

H₂O

Could this possibly be the solution to one of the longest standing mysteries of the Vision?  Stay tuned folks...I'm sure this is going to get interesting!

David

DEEP!  A quickening may be near.

actually, the original Yamaha manual mentions weak magnets as a possable diagnostic problem...

I finally found a small compass and checked out the magnets on a parts bike I picked up a few months ago. I know its had a replacement stator because it has a Ricky stator decal on the rear fender and the stator looks to be in excellent condition, anyway, the magnets were NSNSNS for all six magnets for whatever thats worth.   BDC

I thought I mentioned to H2O WAAAAAY back. If you have replaced all parts and are NOT running damn driving lights. That the issue  MAY BE the flywheel or wiring harness.  PS. others have discussed this "off line". Note: most 83's have less stator issues. The flywheel may be different.  I have noticed one manufacturing difference of the flywheel from my 5 XZ's that I won't go into. I.E- Treedragon has a good point.

So, the word is...  If there is a DOUBLE you are in TROUBLE.

good= NSNSNS or SNSNSN :) :)

BAD>> NNSSNS  of any combination of two norths of souths side by side.  >:( >:(

Do we all concur?? :police:

Quote from: jasonm. on January 17, 2010, 12:45:24 PM
I thought I mentioned to H2O WAAAAAY back.

You did...after we talked about in Syracuse last year... ;)

Quote from: akvision on January 17, 2010, 04:01:00 PM
So, the word is...  If there is a DOUBLE you are in TROUBLE.

good= NSNSNS or SNSNSN :) :)

BAD>> NNSSNS  of any combination of two norths of souths side by side.  >:( >:(

Do we all concur?? :police:

:) Yes...

Thanks Tiger...my memory sucks....got that Scotch?  I need a drink

I did do a flywheel change in one of the many stator replacements.  Still say it was a FUBAR new OEM type R/R that I trusted.  The next R/R I installed gave me 1500 miles before that R/R fried.  Then I swapped back to the previous R/R & got the typical 1000 additional miles out of the stator.  (2500 total on that one).  I have another R/R (from RM Stator) in it now and got close to 1000 miles on the whole setup before the riding season ended.  I'll have to wait for it to warm up around here (global warming my @$$) and riding season to begin again so I can see if I get more miles again.

H₂O

Yes, keep track of your mps for us :)  (sorry I could'nt help it)

Quote from: h2olawyer on January 29, 2010, 04:53:26 AM
(global warming my @$$)

I don't think global warming is localized to just your @$$ :-)  Though with the seat warmers in my car on full, it can feel like that...

H2o, I feel your pain. But you are swapping parts...but this is not how to trouble shoot things. Would you take your car to a "mechanic" who swapped parts before doing the proper diagnostics? I suspect you are not an electronics tech like me. You need a good DVOM and knowledge on how to test stuff. YOU NEED TO FIND THE CAUSE of the stators failing.And have all your replacement stators been Yamaha OEM or some crap China stuff?  I believe I have stated most of the above...before. YOU SHOULD HAVE NO EXTRA ELECTRICAL LOADS ON THE BIKE. No driving lights, NOTHING. Then start from scratch. Otherwise you are just sticking your "head in the sand".   Also Treedragon...I don't know the watts of those 2 headlights. But you also could be getting to cooking stator time soon. These bikes have very little spare wattage to give.

Quote from: jasonm. on January 29, 2010, 07:53:31 PM
H2o, I feel your pain. But you are swapping parts...but this is not how to trouble shoot things. Would you take your car to a "mechanic" who swapped parts before doing the proper diagnostics? I suspect you are not an electronics tech like me. You need a good DVOM and knowledge on how to test stuff. YOU NEED TO FIND THE CAUSE of the stators failing.And have all your replacement stators been Yamaha OEM or some crap China stuff?  I believe I have stated most of the above...before. YOU SHOULD HAVE NO EXTRA ELECTRICAL LOADS ON THE BIKE. No driving lights, NOTHING. Then start from scratch. Otherwise you are just sticking your "head in the sand".   Also Treedragon...I don't know the watts of those 2 headlights. But you also could be getting to cooking stator time soon. These bikes have very little spare wattage to give.

Here's the thing though:

Its a shunting regulator, and a permanent magnet charging system. The stator is at full load, 100% of the time. The regulator demands 100% power at all times. The waste heat is coming out of the regulator, not the stator. The stator supplies the voltage, not limits it. The permanent magnet system can't 'overload'. It's already at full field, all the time (permanent magnet, right?). The only thing you accomplish by removing all electrical load is in fact putting MORE heat out through the regulator. Presumably, the regulator can handle the heat. Using every single watt you can possibly get out of the stator will do nothing, in fact all that electrical energy that would otherwise be converted right into heat energy by the regulator is shifted to other purposes, lights, heated grips, whatever. Here's what will happen when you overload the vision system; The battery drains and everything shuts off (actually, tci dies at about 10 volts). I could connect an arc welder to the battery when the bike is running and all that will happen is the regulator will tap out (every ounce the stator is giving goes to the device, no more than its already outputting) the battery will discharge because the system drops below 14.5 volts, and stuff just quits.

What you're saying applies to active rotor alternator generators. If i keep putting more and more and more crap onto the electrical circuit on, say, my chevy cavalier (was going to say the rd400, but i think thats actually at full field all the time anyway). The regulator demands more and more and more current, so it increases field voltage more and more and more until it's full fielded. Alternators don't take full field very long (unless its a heavy duty model) and eventually that extra magnetism cutting the stator windings WILL overheat the thing. The difference is the vision stator is ALREADY full fielded, an alternator is not. When i connect my arc welder to my cavalier, sure it will discharge the system because theres no way im putting out that much power, but it will blow up the alternator at some point because its not designed to go full field very long, maybe once at startup when the a/c is on.

On and on we go into the age old angry electron debate, but long story short:
Vision stator is full fielded 100% of the time
Regulator demands full voltage 100% of the time
Extra electrical 'loads' actually don't 'load' anything, then unload the regulator if anything
If you unplug the R/R from the stator, nothing happens. Current doesnt exist with no circuit (heading off that argument ahead of time)

I havent put much thought into the wrong polarity magnet idea, doesnt make sense to me really but a whole lot of things dont, i've always had a pet theory that an out of balance rotor will make unfriendly vibes (undetectable frequency) and shake the windings enough to eventually short. Really, though, i could see how an out of balance magnetic field could do the same thing. The stator armature is steel, you know, at high rpms i could see how it flexes minutely with the different polarity fields. I could also see how a double strength polarity could flex it much more, and at higher rpms i could see a resonance happening...


Edit: Actually, now that i think of it, they do make welder kits that run off the serpentine belt. Really high quality high heat alternator, but yes, they too can run at full field, but they're designed to do it. Never thought of a need to run a bead if i'm out and about, i guess if you're offroading though :)

...inanecathode...You are oversimplifying the system and how it works.   Yes the system is always working and excited. BUT NOT AT MAX power.Ours does not get near max till 3000rpm or so. Thus not getting your "max  AC voltage" till then.  And that's converted to about 250w 14vdc in our system. ALL A RESULT OF RPM AND AVAILABLE GERERATED FLUX. FLUX IS ALWAYS LOWER AT LOWER RPM. And that's where the R/R comes in. As we know, to change AC to DC and dump what's not needed. A.K.A. TO take what's available and change it into what we need. SAY IT AGAIN,  "max is not available all the time." Jeeeeezzzzz basic law of generator design...More rpm = more available power.If you exceed the system's available output by excessive draw, you are going to have problems. Look in the back of the service manual. PS> I have built generator/alternators . All generate electricity and the byproduct is ALWAYS heat.heat. This just happens to be one design with less than stellar parts and ability to draw the heat out.If you can't get 7-10k out of a stator...you surely have something very wrong But still, I am on my original stator close to 33kmiles. Maybe I'm the luckiest SOB out here?

No I think Kenny S. is the luckiest SOB.  He past the 100,000km mark and still on the OE stator, if I recall correctly.

When I die and have my exit interview with The Lord, and if I'm allowed to speak, one of my first questions will be "What causes' V stators to fail often?".

I don't think the answer is down here.

Well gee QBS, fat lot of good that'll do us, we'll still be stuck down here unless God has a good ISP, because your gonna have to let us know the answer.

Gentalmen of the forum, I deal with old British motorcycles quite a bit and I'm shure any of you that have been around motorcycles for awhile have heard many of the Lucas tails of woe. The Lucas AC systems worked just like the the system on the Vision with one exception, they did not use a regulator, but a rectifier and one or two Zener diodes in a heat sink to get rid of the heat, these systems were quite reliable, poor conections and cheep switches were the biggest probblems, but the main reason a stator would fail is not enough clearance between the stator and rotor magnets. Because of poor assembly quality and or crankshaft flex the rotor would touch a stator pole and local overheating would take out the stator. My point here is when you examine a failed stator make shure in look for any signs of the flywheel magnets touching the stator poles.

 Ken G.

Quote from: jasonm. on January 30, 2010, 01:02:04 PM
But still, I am on my original stator close to 33kmiles. Maybe I'm the luckiest SOB out here?

Sorry Jason, at best you're the second luckiest...  (45,000 miles on original stator)  ;D

Quote from: jasonm. on January 30, 2010, 01:02:04 PM
...inanecathode...You are oversimplifying the system and how it works.   Yes the system is always working and excited. BUT NOT AT MAX power.Ours does not get near max till 3000rpm or so. Thus not getting your "max  AC voltage" till then.  And that's converted to about 250w 14vdc in our system. ALL A RESULT OF RPM AND AVAILABLE GERERATED FLUX. FLUX IS ALWAYS LOWER AT LOWER RPM. And that's where the R/R comes in. As we know, to change AC to DC and dump what's not needed. A.K.A. TO take what's available and change it into what we need. SAY IT AGAIN,  "max is not available all the time." Jeeeeezzzzz basic law of generator design...More rpm = more available power.If you exceed the system's available output by excessive draw, you are going to have problems. Look in the back of the service manual. PS> I have built generator/alternators . All generate electricity and the byproduct is ALWAYS heat.heat. This just happens to be one design with less than stellar parts and ability to draw the heat out.If you can't get 7-10k out of a stator...you surely have something very wrong But still, I am on my original stator close to 33kmiles. Maybe I'm the luckiest SOB out here?

I thought it was a basic assumption that we're not talking about sitting there at idle, that's obviously not max power. I dont know how you get ten thousand miles out of a stator staying below 3k rpm, but everyone else i know rides above that, meaning the stator is under 100% load 100% of the time. Rereading what you wrote i think about 5 times, i dont think you're actually refuting what im saying, sooooo... Yes, the stator is under 100 percent demand 100 percent of the time. The heat comes out in the regulator, not in the stator.

Actually, Jason is correct. And you are to a point as well.  For a given RPM, the stator is producing a consistent voltage.  Say at 5000 RPM, the stator generates 20 volts RMS.  The regulator/rectifier will clamp that down to 14 volts (or around there).  So you are correct, the voltage is always at max coming out of the regulator/rectifier.  That is what the shunt is for in the regulator/rectifier.  And that does produce a lot of heat in the R/R.

However, that is not all that is going on.  The voltage is controlled by the RPM on the stator.  The current draw is controlled by the resistance in the bike after the R/R.  As you add more load, that resistance is going to drop, because all of those loads are in parallel, you can calculate the load as 1/R1 + 1/R2 + 1/R3 ... = 1/Rtotal.  You have 14 volts, V = IR gives you I = V/R.  As R drops because of more loads your current I has to increase given that your voltage is constant.

This is exactly the same thing as a generator powering a house-hold current.  It chugs along happily while the load is low, but as the load increases it uses more power to maintain the voltage.  

Since the current is now increasing, the heat produced in the wires in the stator (remember they are at constant voltage for a given RPM) also increases. Power output of a resistance is P = VI.   Voltage stays constant, so as the current goes up the power has to go up. That power is heat.

What clicked this for me was someone reminding me that the voltage is directly related to the RPM in a generation circuit. (yes, it's been a long time since I thought about this in physics, over 2 decades now.  In that time I got comfortable with slightly incorrect ideas.)  Given that reminder, the rest fell into place given the basic formulas  Voltage = Current * Resistance and Power = Voltage * Current.  That and I was riding an exercise bicycle that has an adjustment which basically is the same as increasing load on the bike.  When I increased the load, I had to work a lot harder to maintain the RPM.

I don't know if this changes anyones mind or not, but it's my belief.

Brian

Has anyone here tried a stator from RMSTAOR?  At the very least they have a great application chart that shows many other bikes that use the same stator, so it opens up a pretty big field to re cycle from.  They also have regulator/rectifier in a couple versions.  One listed as "heavy duty".  Anyone?

 :) Here ya go fret...(I posted this some time ago... ;) )

:) Here is a list of other bikes that use the G7 stator (same as the Vision... 8) )

YAMAHA...

1987-96 XV535 Virago
1988-95 XV750 Virago
1992-93 TDM850
1986-88 XV1000 Virago
1987-97 XV1100 Virago

HONDA...

1983-86 VT500c Shadow
1983-84 VT500FT Ascot
1988-01 VLX600-VT600 Shadow
1987-96 XL600V Transalp
1996-99 CBR900RR
2000-03 CBR929RR

SUZUKI...

1985-87 VS700 Intruder
1992-99 VS800 Intruder
1990-92 VX800
1998-01 VL1500 Intruder

APRILLIA...

1999-02 SL1000 Falco
1999-02 RSV Mille
2001-02 RST Futura
2002.... ETV Caponord

BMW...
1997-01 F650

Cut and paste or print off ;)

There are others...feel free to add on to this thread 8)

                   

I did a quick ebay search for "XV1100 + stator" and came up with these babies.  Cheaper too.
http://shop.ebay.com/?_from=R40&_trksid=p3907.m38.l1313&_nkw=XV1100+%2B+stator&_sacat=See-All-Categories

And cheaper still....
http://shop.ebay.com/i.html?_nkw=VS700+%2B+stator&_sacat=0&_trksid=p3286.m270.l1313&_odkw=VL1500+%2B+stator&_osacat=0

HONDA cheaper still......
http://shop.ebay.com/i.html?_nkw=VT500FT+%2B+stator&_sacat=0&_trksid=p3286.m270.l1313&_odkw=VT600+%2B+stator&_osacat=0
http://shop.ebay.com/i.html?_nkw=VT500c+%2B+stator&_sacat=0&_trksid=p3286.m270.l1313&_dmpt=Motorcycles_Parts_Accessories&_odkw=VT500FT+%2B+stator&_osacat=0

$28 for the Honda one.What a difference!

I'm currently running a shadow stator in one of my Visions....

what one needs to keep in mind is that the "list" is based on inner and outer diameters measurements of the G7 type stator...

although lots of them are the same "size", their wiring / windings may be slightly different.... the exit points of the wiring on the shadow stator I used  just barely lined up where the wires need to be (held in place with that holder thingy)

While replacing Vision stators I had a lot of time to think about this:

The stator open-circuit voltage increases with RPM, say some constant V * RPM.

The stator winding acts like an inductor, and its impedance increases with RPM (frequency), say some constant Z * RPM.

Here's the approximation part:
At most RPMs, the open circuit stator voltage is much greater than 12, so the load seen by the alternator appears to be a short circuit. Another way of saying this is that the output current is limited only by the alternator internal impedance. This approximation is not very good at idle, but at any riding RPM, e.g. 3500 or more, it's pretty good.

Given that approximation, the output current is constant, i.e. (V*RPM)/Z*RPM).

Some of the output current runs the lights and the ignition, the rest heats the regulator. The exact same total current flows through the wires of the stator and heats them up too.

Same current, same heating effect all the time. Unlike an excited-field alternator.

These hot wires are 'cooled' by oil splash, and the oil is pretty hot to start with.

That's why the insulation gets black and eventually breaks down, allowing the stator to short to ground. Because it's producing full output all the time and current in the wire generates heat.

This design is cheap, and it usually lasts longer than the warranty. Makes me sick.

Quote from: GeorgeRYoung on February 02, 2010, 03:34:30 PM
Here's the approximation part:
At most RPMs, the open circuit stator voltage is much greater than 12, so the load seen by the alternator appears to be a short circuit. Another way of saying this is that the output current is limited only by the alternator internal impedance. This approximation is not very good at idle, but at any riding RPM, e.g. 3500 or more, it's pretty good.

I think there is a flaw in this approximation.  Assume that the voltage is rectified to always be positive.  

Anything above 14 volts is shorted to ground via a resistor, or something equivalent.  What that means is that for everything below 14 volts, the outside resistance is the bike electrics, for above 14 volts it is the regulator.  So you basically have a system that has two resistors, one that is active below 14 volts (the bike load) and one that is active above 14 volts (the regulator).

What this also means, practically, is that the more load you put on the system the more power it takes from the engine to drive that load (because the current is increases with the load).

Unfortunately, the way to prove this would be to see whether there is a decrease in power available when you turn on more load.  If you hooked up your motorcycle regulator to a generator/stator on a bicycle so that you are providing the power (there are lots of people who have done this) then you can actually tell when you add more load because you have to pedal harder to keep the current requirements going.

Brian

There is significant heat out of the stator. Why do you think they turn black. Why did Yamaha put a cooling mod. in the Ventures.aka 2 Vision engines ?  Heat is always a result of an AC generator. Flux lines do cause heat. And the faster the engine spins. The more heat thru the windings. But maybe you missed that class? And the regulator gets hot from it's job of doing R/R and it's not rest and relaxation.  Put your hand on the left engine case after starting cold. It gets warmer much faster than the right side. My heat gun does not lie...nor my hand.  Heat is always the culprit. Just which dies 1st...the R/R or the stator?  Inanecathode; I think we are saying the same thing. Just 2 different ways. This Spring I will be installing a MOSFET R/R on both my bikes. These are now on many bikes. Including the latest Vmax. These are suppose to be more efficient at doing the required job. And supposedly less "voltage spikes"...if that's important?

Jasonm, is that MOSFET r/r a modification to the original r/r or another project we have to make ourselves, or an aftermarket item?

Uhg. I stopped counting at six the times this discussion has happened.

Look. Here's how you fix it. Wind a better stator, there. Extremely high temp insulation, cast stator core, epoxy coated stator poles. Doesnt matter how crappy your charging system is, if you can't break it it wont break.

If part of my bike keeps falling off, i'm not going to find a different way of riding so it stays attached, i'm going to bolt that stupid thing down better.

Makes sense.lol

Quote from: fret nut on February 02, 2010, 09:16:32 PM
Jasonm, is that MOSFET r/r a modification to the original r/r or another project we have to make ourselves, or an aftermarket item?

THERE WAS A "GROUP PURCHASE"  on the Venture site I go to. For these MOSFET R/R's. Venturerider.org  I bought 2 of these. I will do this MOD. in the Spring.  FYI, were very inexpensive. I could not resist.

Thanks Jason, keep us posted.

The approximation part:

At 10000 RPM, the open circuit voltage is 100 VAC, the impedance of the windings is 5 ohms, and it's working into a load of 14 volts.
Current = (100 - 14)/5 =17.2A

At 5000 RPM, open circuit voltage is 50 VAC, the impedance is 2.5 ohms, still working into a 14 volt load.
Current = (50 - 14)/2.5 = 14.4A

At 3500 RPM, open circuit voltage is 35 VAC, the impedance is 1.75 ohms, still working into 14 volts.
Current = (35 - 14)/1.75 = 12 A

It's obviously not exactly constant, but it doesn't vary much with RPM.

There is a good artical about a better regulator on eviltwinsbk.com it's even a Yamaha part. Check it out.

  Ken G.

George.DC volts is the result of the R/R after the AC from the stator. Which was never in question. ..

you say "not vary much". You just stated the AC voltage changes with RPMs clearly 10vac/ 1000rpm. This is what I am saying. RPM = voltage AC. The issue is wasted AC causing heat.  AND thank you for your observations.

That Evil Twins discussion is really good.  So much to learn, so little time . . . . . . .  :)

Quote from: jasonm. on February 10, 2010, 08:09:15 PM
. . . snippety . . . you say "not vary much". You just stated the AC voltage changes with RPMs clearly 10vac/ 1000rpm. This is what I am saying. RPM = voltage AC. The issue is wasted AC causing heat.  AND thank you for your observations.

Not one to give up:

When the RPM rises 300% (from 3500 to 10000) the current rises only 50% (12A to 17A), that's what I mean by 'not very much'.

The heating of the wires is caused by the current (that 12 - 17 A figure) and the resistance of the windings, which is constant. The current also flows through the inductive component of the impedance (i.e. the part that varies with RPM), but this causes no heating.

The fact that both the open-circuit voltage and the impedance vary with RPM is not relevant to heating the wires, except that it causes the current to be 'approximately constant'.