Charging Issues. -1980 xs650 special-help

[nomad007]

Hello,
I have a 1980 xs650 special which has charging issues. It had been running great than I rode it 100 miles and it died and would not recharge while riding. I first replaced the rotor the old one metered 1.5 - new now meters 5.5 but did not fix. Replaced regulator - did not fix - tried another stator no change - both stators measure .8 on all white wire combos and OL when grounded- did not fix issue, So again it starts but headlight and headlight indicator do not come on ( which they always did before) snd while revving 2k 3k + meter never goes over 12.7. Battery meters 13.18 when off. I unhooked the wires on headlight reserve grey box by battery and jumpered blue/blacl and bluel/yellow wires - still no headlight. Also cleaned ground cable to frame - it was already pretty clean - this bike is in really clean condition for its age. So to recap the rotor meters good - stator meters good- rectifier meters good- Oh I also replaced all fuses with new( it does have original fuse box but it metered correctly and it is in good shape-I ordered a starer safety head light relay off eBay. hoping that might help but I am guessing . would that relay cause the charging issues? I will also say those brushes are a bit finicky but I installed the new ones like the old ones were and it always worked before - I have had this bike about 4 months and put about 800 miles on it so far- Anyway - any help would be appreciated this forum is awesome - I am trying and trying to learn more - Thanks Curly for your guide- it has been very helpful !

 

[Jim]

Good looking bike. Course, I'm a bit biased

No, the relay won't cause a charging system problem.

Give us some good, close up pics of the brushes, rotor, stator and connectors, reg/rec and connector, fuse box and battery connections.
Good clear pics are helpful in solving problems.

 

[Jim]

Good looking bike. Course, I'm a bit biased

Here's the reason I'm biased. My '80SG

 

[nomad007]

Here's the reason I'm biased. My '80SG

View attachment 345816

That is a beauty - I canceled my ebay headlight relay- I am going to install a bladed fusebox and new brushes and if that still does not work I will post a lot of pictures. and hopefully figure it out - at least I am learning about wiring haha

 

[nomad007]

Good looking bike. Course, I'm a bit biased

No, the relay won't cause a charging system problem.

Give us some good, close up pics of the brushes, rotor, stator and connectors, reg/rec and connector, fuse box and battery connections.
Good clear pics are helpful in solving problems.

new brushes. reinstalled rotor. it meters good stator meters good. - still no headlight. and not charging. - I usually leave my battery on a tender - I am leaving it unplugged for 24 hours to see if it drops significantly - although it has always read good because it had been charged if it had an issue like bad cell would that cause the issue even if it was charged up?

 

[nomad007]

new brushes. reinstalled rotor. it meters good stator meters good. - still no headlight. and not charging. - I usually leave my battery on a tender - I am leaving it unplugged for 24 hours to see if it drops significantly - although it has always read good because it had been charged if it had an issue like bad cell would that cause the issue even if it was charged up?

Also I don't think I am even passing the Slap test

 

[Jim]

Those brushes are not installed correctly. That could be your problem. Hang on and I'll find some pics.

 

[Jim]

On the brush holder, there's a notch molded into both for the pigtail to slot into. If they're not slotted in, the brush might not be long enough to touch the rotor slip rings. Fix that and we'll go from there.

 

[nomad007]

On the brush holder, there's a notch molded into both for the pigtail to slot into. If they're not slotted in, the brush might not be long enough to touch the rotor slip rings. Fix that and we'll go from there.

View attachment 345843

great info I did not know unfortunately nothing changed yet

 

[nomad007]

thanks Jim for your help

 

[Jim]

great info I did not know unfortunately nothing changed yet

It's progress though.

See the needle nose in my pic above? What I'm doing is shorting the green wire to ground. The green is normally grounded through the reg/rec. Grounding with the pliers bypasses the regulator. Start the bike and watch the voltmeter as you rev it to 3k revs or so (get a helper or figure it out).
Soon as you ground it, volts should take a big jump... like 15v or higher. Don't leave it grounded longer than it takes to look at the meter lest you burn something out.

If volts jumps up, the reg/rec (or wiring) is bad.
If volts does not increase, we've more test to try.

 

[nomad007]

It went from 12.53 to 12.9. thats it

 

[Jim]

OK, measure resistance across the rotor slip rings and each slip ring to ground. Removing the inner brush helps here.

Ring to ring should be about 5Ω
Each ring to ground should be ∞ (open... infinity)

 

[nomad007]

I had to remove stator to get a good reading this is a "new" rotor from Mikes XS. my old one measure 1.2. - should i clean black stuff off - is so with what - I have another stator cover too- i tried it earlier but i probably did not have brushes intalled properly. - also i removed and installed rotor with ompact gun. - could i have put in on too much - i just gently buimped it but who knows. - both stators check out measuring white wires. - again many thanks for your help

 

[Jim]

What about each ring to ground?

Those Mike's rotors have a history of not standing the test of time. Hopefully you kept your old rotor. I rebuild them for $105.
Might wanna consider that so you've a spare.

 

[nomad007]

sorry yes ring to ground ol. or infinity - yes i have it the old one and that is a great to know - oh you are the famous Jim awesome

 

[nomad007]

also I hve had this for about 4 months usually do a 70 mile ride on Sundays- last time i rode it I went 110 miles and around 90 the headlamp indicator got weaker and went out and then I barely got it back to my friends house and had to trailer it home. I always have it plugged into a battery tender if not riding- the battery meters 13.18. with key off - i was going to leave it unplugged for 24 hrs and check it - it came with the bike and is lead acid - i dont know if that could contribute to it or not, but it never was an issue before but maybe i never pushedx it to complete failure before

 

[Jim]

OK, lets see if your rotor is magnetizing. With everything connected, hold a wrench about a half inch away from the rotor nut. Turn the key on and the rotor should suck the wrench on to it.

 

[nomad007]

no. it does not

 

[Jim]

OK, now do the same thing again with the needle nose grounding the outer brush. Magnetize now?