Slow to build charging voltage

[C.V.]

first off - '79gs850g, new electrex RR, stator output within spec, all connections have been cleaned/replaced as needed, then double checked again! The only thing NOT replaced (other than the stator) in the charging system is the battery.

I can get over 14 charging volts, but it rolls up very slowly. It is lower than I would like at idle (less than 13). When I roll up the RPMs, it takes maybe 30 to 45 seconds for it to creep up to 14+, it just slowly and steadily increases. This is not how it behaved when I first rebuilt the system.

Could this be because of the battery? Any explainations?

Thanks guys...

[spyug]

Oddly enough, it could be the battery causing grief.

I can't really explain why but I have experienced something the same myself and I've been told by people more in the know that a good battery is a must for the electrical system to function properly.

In my case on my XS I couldn't get proper charging voltage until I changed out the ( standard lead acid) battery for a new one. Testing the old one showed three cells that would not take a full charge.

Can you try another battery?

As far as the lower voltage at idle that is likely ok but it should snap to higher voltage much quicker than that (i.e. as soon as you touch the throttle). It does with the XS (highest charge at around 2500 rpm) but oddly with the GS it is almost the reverse. Mine shows strong (14+)charging at just around idle but drops off to 13 or less over 3000/3500.

Hope this helps a bit.

Cheers,
Spyug

[C.V.]

Oddly enough, it could be the battery causing grief.

I can't really explain why but I have experienced something the same myself and I've been told by people more in the know that a good battery is a must for the electrical system to function properly.

In my case on my XS I couldn't get proper charging voltage until I changed out the ( standard lead acid) battery for a new one. Testing the old one showed three cells that would not take a full charge.

Can you try another battery?

As far as the lower voltage at idle that is likely ok but it should snap to higher voltage much quicker than that (i.e. as soon as you touch the throttle). It does with the XS (highest charge at around 2500 rpm) but oddly with the GS it is almost the reverse. Mine shows strong (14+)charging at just around idle but drops off to 13 or less over 3000/3500.

Hope this helps a bit.

Cheers,
Spyug

That helps! Thanks bro. I wasn't sure if a bad battery could prevent proper charging voltage. I still think the slow roll up is odd, it will be interesting to see if a new battery corrects that.

[Nessism]

My guess is a bad R/R, or a bad ground. Did you run the R/R ground direct to the battery? Not sure about your bike but most GS's ground the R/R through the battery box, which is rubber mounted. Very poor design.

[C.V.]

My guess is a bad R/R, or a bad ground. Did you run the R/R ground direct to the battery? Not sure about your bike but most GS's ground the R/R through the battery box, which is rubber mounted. Very poor design.

Yes, I ran the ground directly to the Batt when i replaced the RR about 4 months ago. I am currently choosing not to believe it is the RR, partly because I am getting charging voltage eventually, and partly cuz I just paid 100 bucks for the damn thing! I am confident it is not a connection...(but it never hurts to triple check...)

[BassCliff]

Cooking with electrons

Hi Mr. C.V.,

The first time working on the electrics on my bike was a process of elimination. I cleaned connections and grounds, ran a ground wire from the r/r to the negative battery terminal. It helped for a while. I eventually replace the r/r with a Duaneage special. That helped for a while until further troubleshooting revealed a bad stator. Replacing that helped for a while. When it started undercharging again I figured the only thing left was the battery. After replacing it with a Yasusa AGM unit, I've had no charging issues for the last year and a half.

Thank you for your indulgence,

BassCliff

[C.V.]

Hi Mr. C.V.,

The first time working on the electrics on my bike was a process of elimination. I cleaned connections and grounds, ran a ground wire from the r/r to the negative battery terminal. It helped for a while. I eventually replace the r/r with a Duaneage special. That helped for a while until further troubleshooting revealed a bad stator. Replacing that helped for a while. When it started undercharging again I figured the only thing left was the battery. After replacing it with a Yasusa AGM unit, I've had no charging issues for the last year and a half.

Thank you for your indulgence,

BassCliff

Sounds just like my story! Thanks all you guys for the input! I am going to rplace the batt, and we'll see what happens! Thanks again guys, The GSR and its folks are the best!

[BassCliff]

Oops, I meant a Yuasa battery. I can't spell today.


Thank you for your indulgence,

BassCliff