Aftermarket charge rotors

Measure the voltage (key on engine off) at the battery and at the brown wire going to the regulator and let us know what you get. If you're over a .3V drop (difference), the regulator's gonna work the rotor harder. Turning the light on might be putting it over the top.
Key on and the stop switch in the run position the volts are 11.97 battery, 11.86 regulator wire. Key on and switch in off position volts 12.4 show only a .01 difference between battery and brown wire at the regulator.
 
Key on and the stop switch in the run position the volts are 11.97 battery, 11.86 regulator wire. Key on and switch in off position volts 12.4 show only a .01 difference between battery and brown wire at the regulator.
OK... so that's good. Did you check the headlight wattage as Aldo suggested? Maybe drawing more than the alternator can keep up with? Also, make sure hi and low beams aren't on at the same time? A 50/40 bulb would draw 90 watts if that were the case.
 
Can you check batt. voltage with key on eng off.... headlight off and headlight on?
 
12.4 light off, drops to about 12 flat light. Losing 10th of a volt every few seconds, battery also hasn't been on the tender in a while. 11.96 with high beam
OK... just tested my 80SG with 1yr old batt....
Key on= 12.0V
Started bike so headlight came on then killed engine with kill switch= 11.5V
1 minute= 11.5V
2 Min= 11.5V
3 Min= 11.5V
4 Min= 11.5V
5 Min= 11.4V
Turned light off and 15 seconds later batt. had recovered to 12.0V
Do the same test with yours and see how it fairs.
 
I had put the charger on about 40 minutes ago so I think my beginning voltage was a false high.

Key off 12.9

1: 12.50
2: 12.45
3: 12.41
4: 12.37
5: 12.34

Recovered to 12.60 after key off
 
Well that doesn't point to a weak batt. or a problem in the lighting circuit. About all I can come up with is you either put a bad reg/rec in it or you're having terrible luck with Chinese rotors.
 
Well that doesn't point to a weak batt. or a problem in the lighting circuit. About all I can come up with is you either put a bad reg/rec in it or you're having terrible luck with Chinese rotors.

I just bought a used oem rotor off another 77 from ebay. Says ohms checked out in the description, will run and see what happens. If it's no good I'll send it to ya for a rewind
 
I just bought a used oem rotor off another 77 from ebay. Says ohms checked out in the description, will run and see what happens. If it's no good I'll send it to ya for a rewind
Keep us updated and good luck.
 
Koenig: if you still have trouble and are confident that your rect-reg is good then Jim rewinds rotors and they are better than new and certainly miles better than the cheap chinoiserie knockoffs.

Highly recommended.

Pete
 
Koenig: if you still have trouble and are confident that your rect-reg is good then Jim rewinds rotors and they are better than new and certainly miles better than the cheap chinoiserie knockoffs.

Highly recommended.

Pete

That's the plan if this used OEM doesnt work. I'll send the unit in for refurb. Might send it in over winter even if it does work out just to know its 100%. Reg/rec should be good, new units from the guy at Oregon motorcycle parts. Maybe 3-4 hours total run time on them
 
I had a new chinese rotor and lasted all but 100kms. Put old one back in that tested low in resistance (3.6 ohms) and has been working fine since. :shrug: Got 1176 kms on the clock now with no issues and charging to 14.2 volts with diy reg / rec. Good luck hope it all works in the end. I will never use chinese crap ever again. Live ya learn I guess! I would trust used OEM vs new chinese any day. JC
 
A friend of mine owns an electronics manufacturing business. A customer called and asked "how much do you charge for a 'widget'? He quoted them '$1.00'. They told him they're saving money by buying 'widgets' from China for '$0.60' each, but they have dumpsters full of defective 'widgets'.
How much are they saving? With the exception of "widgets" and theoretical dollar figures, it's a true story. The moral? Buy the good stuff. It's money well spent. :twocents: ...or, as a wise man once said "If you want good, clean, quality oats, you have to pay a premium price. If you want oats that have already been through the horse, there is a substantial discount"... :wink2:
 
Well I got the used OEM rotor off another 77 that tests good and cleaned the rings up. So hopefully I'll have time to get it in this weekend and see if it holds out.
 

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