Charging Voltage

[ssco156]

I've just replaced the stator and regulator on my 1981 GS450. The output voltage is a constant 14.8V from idling to 4000 rpm. With the headlight switched on, the voltage decreases to about 13.3V at idling going up to 14.5V at 4000 rpm. Is this normal? I always ride with the headlight on but I'm still worried that the battery will be overcharged. Thanks for any help.

[LAB3]

Sounds like everything's doing what it's suppose to. Summer is winding down fast, get out there and enjoy it!

[Nessism]

Well, your stator is strong. Did you install an SH775 R/R to protect it? And did you rewire the charging system to avoid the stator loop wiring through the hand control and improve the R/R grounding? The 450 grounds the R/R through the battery box which is a horrable method. High charging voltage on the 450 is known to take out ignitors so you have to pay attention to how the system is working.

[tom203]

14.8 is too high....make sure your r/r has an improved ground to battery . In fact, bite the bullet now and get a SH-775, cuz it's superior to any of the shunt r/r's.

[posplayr]

OP has not said what he has done to the charging system so we will have to assume it is stock. My 1981 GS750E had a single leg (SCR) regulator which I think are the ones that tend to overcharge (because they only regulate on one leg).
Since the reported voltage with lights off/on is 14.8v/14.5v respectively, that would indicate that the stator is potentially reaching max power output with a headlamp on. It could be that the stator is slightly burned (reduced output) which is why the voltage only achieves 14.5V with headlamps on.

Could be a combination of factors, burned stator, over-charging single leg R/R and probably poor grounds and connections although I don't know how this would contribute to overcharging.

Basically we are probably just looking at a well worn 40 year old flawed charging system.

[Nessism]

OP has not said what he has done to the charging system so we will have to assume it is stock. My 1981 GS750E had a single leg (SCR) regulator which I think are the ones that tend to overcharge (because they only regulate on one leg).
Since the reported voltage with lights off/on is 14.8v/14.5v respectively, that would indicate that the stator is potentially reaching max power output with a headlamp on. It could be that the stator is slightly burned (reduced output) which is why the voltage only achieves 14.5V with headlamps on.

Could be a combination of factors, burned stator, over-charging single leg R/R and probably poor grounds and connections although I don't know how this would contribute to overcharging.

Basically we are probably just looking at a well worn 40 year old flawed charging system.

I've just replaced the stator and regulator on my 1981 GS450.

See above......