Charging woes

[Ta2Mike]

Ok here is my dilemma. Ive recently done a mass overhaul of my 79 850. Ive replaced the stator, the R/R was replaced about 3 weeks before i wrecked it so its pretty new. Ive done the stator test, good all around. Ive cleaned every connection I can find. Yet when I run tests it still doesnt seem to be charging. I cant figure it out. All I can think of is maybe my R/R fried in short time it was run before...or Perhaps my battery is on its way out. Ive read stator papers religiously over past several days. Any ideas?

 

[makenzie71]

Your R/R was new? Or just new to you? Where did you get it?

 

[Ta2Mike]

the R/R was brand new. it was either ricks sport or electrosport.

 

[Flyboy]

Earths, check that you have good earth, this is a source of frustration on many older bikes.
It is possible that the RR is dead, being an electrical item, they can last 2 years or 2 minutes, hense, no guarantee on electrical components.

 

[tom203]

Run a wire from r/r ground wire to battery negative as has been stressed many times. Are all three stator wires going direct to r/r with no silly loop up to headlight switch and back ? If stator is producing juice, it has to going to r/r which either feeds the battery and other stuff or dissipates as heat in r/r- unless the r/r is dead.

 

[posplayr]

The stator pages are intended to provide an expediant means to diagnose the vast majority of charging system ills. You virtually can NOT pass all the tests and still NOT charge. Therefore you must be failing in some part of the test. Where is that?

 

[Ta2Mike]

The test its not passing is the R/R test. at 5k its showing just under 12V. Stator connected directly to R/R. Im guessing the R/R has to be bad. Just baffling I guess since its fairly new. Guess I need to source a new one. I just want to ride again.

 

[posplayr]

The test its not passing is the R/R test. at 5k its showing just under 12V. Stator connected directly to R/R. Im guessing the R/R has to be bad. Just baffling I guess since its fairly new. Guess I need to source a new one. I just want to ride again.

what is the highest voltage output you get and what is the RPM?

Do you ever get to 13V?

 

[tom203]

There's always a chance that a stator could pass the open circuit test (> 80 volts across the phases ) and still fail when it started to deliver current to r/r. Is the stator new or used? When you hook everything up and test it does the r/r get hot to touch? With ignition and lights running, the r/r should be working hard to keep up with the power demands.

 

[posplayr]

since both stator and R/R have been change recently I would suspect your connections.

I'm guessing that you are following this


http://www.thegsresources.com/statorpapers4.php

Link to Revised PHASE A of Stator Pages:

The very first test says:

Switch the
multimeter to DC
Volts. Switch the
range to 20 or 50 V.
Connect the
multimeter leads to
the battery
terminals. Start and
rev the engine up to
2500 rpm.​

Check
that the batteryvoltage
increases
from 12.8V to over​

13.5V with RPM
​

​

The format of the pages may be a little confusing but there are a bunch of branches. If you pass this test above then move to the right, if you fail move down. Since you are testing at 5K rpm which is the test to the right but to get there you had to be over 13.5V at 2500 rpm? Did you get that or not?

if you are not getting over 13.5v you test your stator using the open loop test.

The tests assume that you have made an preventative effort to fix the connections as described in the GS charging system link in my signature.

Here is a simple test that is basically imbedded in the stator pages.


MEASURE and RECORD BATTERY VOLTAGE at each step

#1 key off
#2 key on (lights on)
#3 start engine run at 2500 rpm
#4 run engine at 5000 rpm
#5 key off​

 

[boingk]

Earths, check that you have good earth, this is a source of frustration on many older bikes.

Yes, I'd second that.

Run a wire from r/r ground wire to battery negative as has been stressed many times.

Definitely. On checking the earth on my R/R (connector was fine) I then tested the R/R's connector by shorting it straight to a frame bolt. Surprise surprise, the charging coltage shot up to 14.4 volts. The connection to the stock ground point may have been fine, but the ground point itself or the wiring along the way is fouled.

Fix? Wire straight to battery.

Cheers - boingk

 

[Guest]

Do the stator papers for real and you'll know what's wrong. :hand:

 

[Ta2Mike]

R/R is wired to battery as per recommendations. I poured over everything I could find to ake sure best results. After running Stator paper tests it seems everything is shot. R/R test max of 12.5V at 5k. Also Stator test 20V between all legs. Ive cleaned all grounds. So all I can guess is The wiring nightmare is worse than I originally thought and has thus caused my new parts to fry. It would help if the harness hadnt been cut and spliced and rigged by PO so my non electrically inclined self is at a loss for deciphering it fro wiring diagram. Along with the clutch on my car going out 2 days ago. Im at wits end with this. The things we do to ourselves.

 

[posplayr]

R/R is wired to battery as per recommendations. I poured over everything I could find to ake sure best results. After running Stator paper tests it seems everything is shot. R/R test max of 12.5V at 5k. Also Stator test 20V between all legs. Ive cleaned all grounds. So all I can guess is The wiring nightmare is worse than I originally thought and has thus caused my new parts to fry. It would help if the harness hadnt been cut and spliced and rigged by PO so my non electrically inclined self is at a loss for deciphering it fro wiring diagram. Along with the clutch on my car going out 2 days ago. Im at wits end with this. The things we do to ourselves.

The 20VAC out of the stator is at 5K RPM? It should be about 16VAC per 1000 RPM so 20VAC is about what it would be at idle; just asking?

 

[tom203]

Another poster had a stator question on 79 gs 850, so I'll ask a dumb question. When you replaced your stator, does it have the same number of poles as your original unit? Apparently, it should have 12- and your rotor would then need two sets of north / south magnets .

 

[posplayr]

Another poster had a stator question on 79 gs 850, so I'll ask a dumb question. When you replaced your stator, does it have the same number of poles as your original unit? Apparently, it should have 12- and your rotor would then need two sets of north / south magnets .

stator and rotors must match.

So if I have this right the rotor has to place a magnetic segment directly over each pole in a phase at the same time as it spins moving from one pole to the next. So the magnetic segments (on rotor) have to be the same as the number of poles per phase (these are 3 phase systems).

With 12 pole there are going to be 12/3=4 poles per phase. The poles are 360/4=90 mechanical degrees apart.

With 18 pole there are going to be 18/3=6 poles per phase . The poles are 360/6=60 mechanical degrees apart.

 

[BassCliff]

Hi,

Yes, I was reading this thread thinking the same thing.

The stock '79 GS850G uses a 12 pole stator. The '80 and later use an 18 pole stator. I don't know of anyone who sells a 12 pole stator new. You can, however, get them rewound at several places on the internet.

If you put an 18 pole stator in a 12 pole rotor, it won't work. You can replace the rotor with a later one to match the 18 pole stator and all will be well.


Thank you for your indulgence,

BassCliff

 

[Ta2Mike]

I honestly cannot remember if its 12 or 18. I didnt know there was any difference so I didnt pay specific attention. I ordered the part from Dennis Kirk and I believe it is an electrosport. Oh well I guess off comes the side cover to count poles. I take that back, upon looking through receipts its a ricks motorsport. Which appears to be an 18 pole. I still need to take cover off to be certain I suppose but that may be the fly in the serum.

 

[jbs80106]

FWIW, I had an Electrosport R/R not last me a year. They replaced it under warrantee...the replacement has lasted no problems.

 

[Ta2Mike]

Ok upon inspection. I did end up with and 18 poles stator, hence the no charging. So now to source a newer rotor. Now my question is this..is there anywhere I can find a list of bikes wit rotors that will fit? does it have to be off of a newer 850? or will a 750, 1000, 1100 rotor work? obviously most certainly 83 and newer 1100 is out b/c of big end crank.
Thanks
Mike