82 gs850g

[Guest]

Hey guys. I am trying to troubleshoot my bike and could use some help. I have a 1982 GS850G. A couple of weeks ago the battery died which led me down this path.

I bought the battery tender jr and charged it overnight.

Voltage across the battery disconnected from everything is 12.88V

I put the battery in the bike and turned the key to ON and voltage is 12.1V

I start the bike and idle and it slowly works up to 13.1V

Now here is the weird part, no matter how I rev the bike the voltage stays around 13V

I read the "Stator Papers" thoroughly and I am an electrical engineer so I understand the basics now of how the charging system works. However nothing really seemed to cover the voltage not really changing. My best guess is that the charging system is working but only moderately. I am not mechanically inclined so I am reaching out for some advice.

I tried removing the R/R snap connector to measure the continuity through the R/R but the damn thing is stuck. Then I tried to remove the ground wire but that bolt is stuck too. I am so frustrated!


So if anyone more knowledgable than me has any advice or words of wisdom I am all ears!

Thanks

[Brendan W]

A fully charged battery cold ( i.e. some hours after being on a charger or on a run) is 12.6.
A healthy charging system will make 14.4 Volt approx across the battery at 5000 rpm.
13.1 is not enough to charge the battery. The fault could lie in the wiring plugs and connections or the r/r or the stator or a combination.
Find Posplayr's sig and get doing systematic tests and the decision tree he's developed in the Charging Health linkwill lead you in the right direction.
here you go http://www.thegsresources.com/_forum...tem-QUICK-TEST
For future reference it's a sticky at the top of the electrical section.

[Redman]

.....
I bought the battery tender jr and charged it overnight.
.
.
.
I start the bike and idle and it slowly works up to 13.1V..........

Good that you have a "mainanier" charger and not some 20 amp big charger.

Even when everything is good, these charging systems (stator & R/R) do not charge much at all at idle.

.....

Now here is the weird part, no matter how I rev the bike the voltage stays around 13V

....... My best guess is that the charging system is working but only moderately. ..

I would say that 13.5vdc would be working marginally.
You are not charging much at all.

I would say to proceed through the stator papers, troubleshooting as if not charging at all.

.

[wymple]

I've been riding my 81 for 3 years and it doesn't ever get more than 13.8, usually only 13.1-13.2. The battery is always there. Not sure why it's not supposed to be enough when a fully charged battery is 12.7-12.8. I realize it's supposed to be better, but 13.1 is greater than 12.8, no? People keep telling me my charging system is about to implode and I should get a new stator and R/R, but it sure is taking it's time.

[Brendan W]

Not sure why it's not supposed to be enough when a fully charged battery is 12.7-12.8. I realize it's supposed to be better, but 13.1 is greater than 12.8, no? People keep telling me my charging system is about to implode and I should get a new stator and R/R, but it sure is taking it's time.

It's similar to the reason that a 40 psi compressor is not a good move if you want 38psi in the tyre. First off the riding season will be over before it fills the tyre and second it may never do it because the valve will have a pressure drop across it at any reasonable flow rate. But then 40psi compressor guy has almost zero flow for the last few hours of fill.

Clearly your system is functioning to meet your needs. My take on the recommended numbers it that they are target values and represent optimal charge rates. That does not mean that you can't have stable operating at sub-optimal voltages or charge rates.

Unfortunately I cant resist digging and would be poking around the bike looking for the component that was robbing my half volt what I paid for with my gas money.

[mvalenti]

I've been riding my 81 for 3 years and it doesn't ever get more than 13.8, usually only 13.1-13.2. The battery is always there. Not sure why it's not supposed to be enough when a fully charged battery is 12.7-12.8. I realize it's supposed to be better, but 13.1 is greater than 12.8, no? People keep telling me my charging system is about to implode and I should get a new stator and R/R, but it sure is taking it's time.

clearly you havnt driven far enough from home for it to implode..

[Nessism]

First thing I'd do is clean the ground for the R/R and try again. I believe the R/R grounds to the battery box and the box is rubber mounted. Often times that's enough to fix the system.

[wymple]

clearly you havnt driven far enough from home for it to implode..

Three trips, one with my son to Ohio for the air show at Dayton, over a thousand miles total, another to a Guzzi Rally with my son down in Missouri, a tad over 600 miles total, and a solo trip to a Guzzi rally in Wisconsin, a little over 500 miles in all. The Guzzi was being reworked and not yet done.

[mvalenti]

Three trips, one with my son to Ohio for the air show at Dayton, over a thousand miles total, another to a Guzzi Rally with my son down in Missouri, a tad over 600 miles total, and a solo trip to a Guzzi rally in Wisconsin, a little over 500 miles in all. The Guzzi was being reworked and not yet done.

The grounding might work, but and I held off too long as well, replace the reg/rec... Its cheap insurance....