GS550ES not charging

[nateberkopec]

Just about at my wits end here on a charging issue on this bike ('86).

First, HUGE thanks to the Stator Papers for helping me out with some diagnostics as it is.

Things I (Think) I Know:

• Stator works. When revved above 4k RPM, the multimeter shows about 80V
• R/R (at least the diodes) works. All of the "check for one-way resistance" tests are good.
• Wires are good as are the fuses, checked as per the Stator Papers.

What's still wrong:
The bike still exhibits the same behavior: idles at 12.5 v, when revved up to about 2000/2500 will go to 13.5 or so, then drops to 12 or 11.5 when above 2,500.

What isn't working here? I read in the FAQ that this could be a "stator leak under load", but the stator seems to perform fine above 4,500 RPM when I test just the stator?

[posplayr]

Just about at my wits end here on a charging issue on this bike ('86).

First, HUGE thanks to the Stator Papers for helping me out with some diagnostics as it is.




Things I (Think) I Know:

• Stator works. When revved above 4k RPM, the multimeter shows about 80V
• R/R (at least the diodes) works. All of the "check for one-way resistance" tests are good.
• Wires are good as are the fuses, checked as per the Stator Papers.

What's still wrong:
The bike still exhibits the same behavior: idles at 12.5 v, when revved up to about 2000/2500 will go to 13.5 or so, then drops to 12 or 11.5 when above 2,500.

What isn't working here? I read in the FAQ that this could be a "stator leak under load", but the stator seems to perform fine above 4,500 RPM when I test just the stator?

Sound like you have nothing wrog except bad connections most likely between R/R (+) and the Battery (+). See link below with the updated stator pages for better explaination of test diagnosis. Report back on Phase A steps 2 and 3 voltages at 5K RPM.

Finally STEP #3.) Perform Stator Paper Checks. The stator pages checks are not perfect, but they are designed to help you through a process of elimination in determining what is wrong with your charging system. The good news about doing steps #1 and #2 above first, is that when the stator pages say to check your connections you know you already have done it. Here is the update.


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

Link to Revised PHASE A of Stator Pages:

ORIGINAL_STATOR_PAGES

http://www.thegsresources.com/_forum/showthread.php?t=152769

P.S Welcome aboard and for doing your own research finding the stator pages.

[BassCliff]

Greetings and Salutations!!

Hi Mr. nateberkopec,

Yes, as Mr. posplayr mentions, these bikes like clean electrical connections and grounds. Also, run the ground wire from your regulator/rectifier directly to the negative terminal of the battery. A lot of these bikes have r/r units grounded to the battery box which is mounted on rubber to protect the contents from vibration. But this makes for a lousy frame ground connection.

Anyway, I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[nateberkopec]

Wow! Thanks for the responses guys...this really is a pretty amazing community.

posplayr - I did the two new resistance tests you mentioned - .16 V on the negative wire, .25V on the positive wire (both at 5000rpm). I assume about this resistance is to be expected.

My suspicion is now turning to the battery. I had someone try it on a load tester, and he said it tested in the "weak" yellow zone.

It seems that the battery isn't holding up to repeated electric starts very well. I had it on full charge, and after running it in the garage for about a total of maybe 3-5 minutes and a total of maybe 10 starts the battery was toast. This *seems* short to me but since this is my first motorcycle, so I wouldn't know. Thoughts? The battery is also the same one I had in the bike when I bought it (used, certainly had sat through the winter at least) and while it doesnt *look* old perhaps this is the problem I've had all along?

About how much resistance should each of the diodes in the R/R have as well? I did the test outlined the Stator Papers and since my multimeter doesnt have a "diode test" setting, I just tested the ohms in each direction. The ohms should be rather high, in one direction, then infinite (1) in the other, correct?

So, with the following evidence:

• "Weak"/yellow test on the battery
• Stator works at all RPMS
• Bike discharges quickly after 10 or so electric starts
• About 13.5V at 2500RPM and down to 11.X V at 5000RPM+
• Low/Average resistance on wires
• Regulator tests fine (diode test)

I'm concluding its just a weak battery. Thoughts?

[posplayr]

Wow! Thanks for the responses guys...this really is a pretty amazing community.

posplayr - I did the two new resistance tests you mentioned - .16 V on the negative wire, .25V on the positive wire (both at 5000rpm). I assume about this resistance is to be expected.

My suspicion is now turning to the battery. I had someone try it on a load tester, and he said it tested in the "weak" yellow zone.

It seems that the battery isn't holding up to repeated electric starts very well. I had it on full charge, and after running it in the garage for about a total of maybe 3-5 minutes and a total of maybe 10 starts the battery was toast. This *seems* short to me but since this is my first motorcycle, so I wouldn't know. Thoughts? The battery is also the same one I had in the bike when I bought it (used, certainly had sat through the winter at least) and while it doesnt *look* old perhaps this is the problem I've had all along?

About how much resistance should each of the diodes in the R/R have as well? I did the test outlined the Stator Papers and since my multimeter doesnt have a "diode test" setting, I just tested the ohms in each direction. The ohms should be rather high, in one direction, then infinite (1) in the other, correct?


So, with the following evidence:

• "Weak"/yellow test on the battery
• Stator works at all RPMS
• Bike discharges quickly after 10 or so electric starts
• About 13.5V at 2500RPM and down to 11.X V at 5000RPM+
• Low/Average resistance on wires
• Regulator tests fine (diode test)

I'm concluding its just a weak battery. Thoughts?

If you re read the stator pages tests you will see you at the beginning to DO NOT do the test till you have a good battery. So get a good battery and re do the tests.

Right now it is pointing to about 4 different things.