Charging Issues. -1980 xs650 special-help

Well that was as clear as mud; I have no idea what corrected the fault due to all the 'cross talk'.
Shame really.
Not 100% sure, Adam. I suspect it was as he said, the rotor was bad and in the process of changing that, he installed a new Mikes reg/rec that was apparently bad right out of the box. Then we were off to the races.... chasing our tail when it was just the rotor all along.

Look familiar, Adam... an XS and an old Gold Wing in the same stable? ;)
 
Well that was as clear as mud; I have no idea what corrected the fault due to all the 'cross talk'.
Shame really.
Hi Adam - I believe the mikes XS regulator was bad- I reinstalled old one - unplugged and replugged headlight in and it started charging- so it seems like - I was chasing my tail because I put new regulator in - my thinking was upgrading the 45 yo one would be good as to not over or undercharge battery but I was wrong. I have had this bike for 4 months - my usual ride is about 80 miles- I keep to on a battery tender if not using. I guess it could handle that until I went on a 110 mile ride and Arun 95 miles I had issues. The headlamp indicator light came on as soon as I turned the key on and stayed on. I did not know that was not supposed to be lit. The old rotor meters at about 1.4. so this issue has probably been there the whole time I just never pushed it far enough to know. Now on on to a new issue.
 
What I’ve learned over the past 50+ years with bikes is, either the coil works or it don’t , it’s not like it works on and of - it’s either or !
I don’t know how long you have had the bike, but I would go through the complete harness, unplug and replug all connectors - clean and use dielectric grease when reassembling - Florida is humid most of the year and corrosion is an issue as well as mold - I even added an ac to my garage to keep humidity and temp to an acceptable level year round! Before the ac I couldn’t keep it “dry” so to speak.
 
What I’ve learned over the past 50+ years with bikes is, either the coil works or it don’t , it’s not like it works on and of - it’s either or !
For the most part that's true, Niels, but there's exceptions. An old weak coil, such as a 45yr old one can cause the problem Nomad described. Seen a few times on cars and bikes.
The "spark" from the plug depends on the dielectric constant of the fuel air charge in the cylinder. At low rpm, a coil has an easy job of jumping that plug gap. When you open the throttle, you get a big drop in vacuum (increased pressure). That changes the dielectric constant, making it harder to jump the plug gap. An old coil where the insulation is starting to break down can stumble in that situation.
One simple way to find out if that's the problem is to close up your plug gap. If it's a .030", close it down to .015" and see if that helps. If it does, the coil is starting to break down.
I don’t know how long you have had the bike, but I would go through the complete harness, unplug and replug all connectors
That's an excellent suggestion. You don't have to do it all at once, Damon. Print out the wiring diagram, and as you clean 'em, mark 'em off on the diagram. It'll give you much more peace of mind when you're 100 miles from home.
 
Jim you are obviously better educated on this issue than I, thanks for clarification. I’ve just never come around one the worked intermittently. Also I’m not educated as a mechanic, learned from my brother ( which was educated as mechanic as well as electrician in high and low voltage ) so I picked up some skills along the way :). Still recall my dismay when we took my first used moped apart back in ‘72 - I thought it would never work again haha !
 
No worries about it being Sunday...
Look at your meter. You're trying to measure 10-15KΩ on the 2K scale. You always pick a scale large enough for the job. When in doubt, bump the scale up to see if you get a reading.

If that's the original coil, it wouldn't hurt to replace it with a Honda MP08 coil.... a used one off Ebay and not the Chinese repops out there. In a bit of irony, exactly the coil your Gold Wing has... 'cept it has 2 of 'em. They're great coils. I run one in my '80SG. Might be the cause of your problem, but there's another...

Another thing the Mikes Chinese rotor you have has a known issue for is messing with the TCI. And your symptoms of stumbling at low rev's are similar. It's an easy one to troubleshoot.
1. take a quick ride around the block to verify you still have the symptoms.
2. Make sure the battery has a good charge.
3. Disconnect the reg/rec.
4. Take her for a spin and see if that fixes the problem.
5. Let us know if there's any change.

If that doesn't turn up anything, I'd try a fresh set of plugs next... and replace the caps, but we'll cross that bridge when we get there... there's some snakes to look for.

Nice early Gold Wing!! I think they make for a good cafe project.
Darn Mike's XS- started and it sputtered and backfired the same unplugged regulator and it ran like a dream only rode it a mile or so I can test some more but I think that's it. Headlight did not work then but I suppose that is because regulator was unplugged. Plugged it again started sputtered backfired but head light came back on. I guess it is time to send my original rotor to the master- let me know how to do that - Hopefully Mikes will take this faulty stuff back
 
Darn Mike's XS- started and it sputtered and backfired the same unplugged regulator and it ran like a dream only rode it a mile or so I can test some more but I think that's it. Headlight did not work then but I suppose that is because regulator was unplugged. Plugged it again started sputtered backfired but head light came back on. I guess it is time to send my original rotor to the master- let me know how to do that - Hopefully Mikes will take this faulty stuff back
Well that was easy enough... ;)

Send me a PM and we'll get the ball rolling. Here's a link to my rewind thread.

https://www.xs650.com/threads/rewound-alternator-rotor.54276/
 
Hi Adam - I believe the mikes XS regulator was bad- I reinstalled old one - unplugged and replugged headlight in and it started charging- so it seems like - I was chasing my tail because I put new regulator in - my thinking was upgrading the 45 yo one would be good as to not over or undercharge battery but I was wrong. I have had this bike for 4 months - my usual ride is about 80 miles- I keep to on a battery tender if not using. I guess it could handle that until I went on a 110 mile ride and Arun 95 miles I had issues. The headlamp indicator light came on as soon as I turned the key on and stayed on. I did not know that was not supposed to be lit. The old rotor meters at about 1.4. so this issue has probably been there the whole time I just never pushed it far enough to know. Now on on to a new issue.
Thank you for the clarification
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Great thread well done Jim. Some useful checks to follow in here. :thumbsup:
Update. - rode 90 miles today - great weather in Orlando - voltmeter read 14.4 during most of the ride no issues -pulling strong though all gears- we ride out past Clermont to Tavares - Howey in the Hills- Lake Harris and beyond. --another Jim's rotor and knowledge success story- Thanks again Jim!
 
hello everyone
sorry new issue today
went to ride down to the grocery store and initially started and then stalled and then would not start.
the battery and plugs were on the bike when i bought it so i don't know how old they are.
Checked for spark both plugs had good spark - plugs were nice and tan but i don't know how old they are.
they are NGK BP7ES
Also when riding saturday the voltmeter read mostly 14.4 when riding but at some long idles it would go to 11.5 and perhaps 11.3. today after the 3rd start attempt it would read 8.8 seemed to go back to 11.8 or 12 if I left it for a few minutes but after 3 different attempts witing in between still no start = there was a pop like a start but would not catch- maybe I flooded it - will try again tomorrow. During the charging issues timeframe - i had the battery checked by batteries plus and they said it was good just needed a charge. I was going to put new plugs in although these seemed ok and wondered if i should try new battery. It did have that sickly rattling sound starting after the 3 rd attempt in a row to start . Usually I pull choke for a seconf and starts by 2 nd time very reliably. Sometimes it does not even need choke. Anyway wondered if anyone had any insight - hope you are having a great sunday- Damon
 
Also when riding saturday the voltmeter read mostly 14.4 when riding but at some long idles it would go to 11.5 and perhaps 11.3.
That's fairly typical for these bikes. At idle, it's not putting out enough charge to keep the battery topped off... it'll be draining. It helps to make sure the idle is around 12-1500rpm. It'll still read low (volts), but it won't drain the battery quiet as fast.
 
Checked for spark both plugs had good spark - plugs were nice and tan but i don't know how old they are.
they are NGK BP7ES
Although the plugs are most likely good, it never hurts to put a fresh set in there on a "new to you" bike. Now you know how many miles the plugs have on them.
 
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