Curly's Charging System Trouble Shooting Guide

[jmhscout]

Ya it sounds like I just née to be more patient with it and retest again I can ride I about 15 mile
from the slight charge I do get but then the charger comes out. I'll repost after I do a retest thanks for the input

[chattownxs]

I have posted in the troubleshooting section about my headlight but it has now become a charging issue so I will post here. Long story short, I am getting no charge. No matter what rpm. I used Curly's guide and got to step 5 where I removed both brushes and checked resistance with the key off between the slip rings and got absolutely nothing and the same for the slip ring to engine ground. I also went ahead and measured resistance at the 3 white wires for the stator and got .1 ohm at all of them?

[pamcopete]

chat,

The resistance on the white wires is OK. The resistance on the rotor slip rings is not.

It's rare that the rotor fails open. Usually it fails shorted, so you could be lucky and its just a loose wire where the rotor windings is soldered to the plate that holds the slip rings.



I would suggest that you check the resistance again when you get the rotor off because it is easier to measure then. Also, I assume that you used the lowest range on your Ohm meter?

If you do need a new rotor, then you can do no better that:

Gary @ "Custom Rewind" in Birmingham, AL 1 800 798 7282

Do not even think about removing the rotor without the proper tool that you can get either from www.mikesxs.com or if you choose to, Gary may have one he can lend to you.

[chattownxs]

Yes I used the 200 ohm setting which is the lowest my meter has. I will look Gary up if need be. It would be nice if I could just solder the wire back if that were the case but knowing my luck I doubt that is it. Also, I should add that the brushes were way different lengths. The green wire brush was about half the size of the brown wire brush. Would that cause a problem?

[chattownxs]

So today was pretty uneventful. I took the stator off to get a better view at the rotor and slip rings. I couldn't tell jack crap about the connections on the rotor windings. There was about 3 feet of shellac or whatever covering everything. I don't have the rotor puller deluxe so I am forced to do all this with it on the bike. I did recheck the resistance of the slip rings and got nothing. I also went back to step to step 3 and jumped the green brush wire to ground. Expecting an array of sparks with the side cover off but got nothing. By the way I am posting this exact same thing in the troubleshooting section under headlight troubles as I don't know who looks where for new posts and could use all the help I can get. Also, that rotor in the picture above is amazingly clean compared to mine. I seriously have a crap load of that varnish junk on mine. I'm guessing it's normal though. Also, the connections at the windings looked worn like they were rubbing on the stator but there were no marks on the stator. Maybe they are machined to be flush with the rest of the rotor?

[pamcopete]

char....,

Dig around the terminals for the rotor windings and see if you can locate the rotor wire itself. Basically, what happens is that the wire was not soldered properly to begin with and it just comes loose.

[5twins]

It's common for the outer brush to wear more than the inner. It covers more distance in every revolution.

[chattownxs]

I will probably have to wait until I pull the rotor off as I can't see crap in my garage. I am gonna assume that the rotor is keyed so that I don't have to worry too much about messing that up? And 5twins, I never thought of that but it completely makes sense.

[chattownxs]

So my rotor puller came today but there is no way I am getting that nut that holds the rotor on off. I sprayed some PB Blaster on it being careful just to get it on the nut and not the rotor and put it in second gear and stood on the brake and something started skipping. I don't know what it was but it didn't look or sound too good so I stopped. I had a 2 foot cheater bar on a 3/4" ratchet and still nothing. I don't have an impact so any other suggestions?

[xsleo]

It's not easy holding the brake and turning the wrench. Get a helper to hold the brake. Try first gear.
I bought an electric impact wrench from a truckload tool sale. It's not very strong, it wouldn't get the lug nuts loose on my truck, but it's plenty strong for any thing on your bike. Cost about $35. If you have a Harbor Frieght close by they probably have one about the same price.

[chattownxs]

I thought about that actually. Luckily I got the thing off today with the help of my wife standing on the brake. I posted my findings in the charging systems section under Pulling the rotor?
xs650temp.proboards.com/index.cgi?board=Charging&action=display&thread=15119
I will post there until it comes back to a charging issue other than a faulty rotor.

[bfeltxs]

I too have had electrical problems on my '79 XS.

I've seen many 'troubleshooting' guides, but was never clear enough to venture in. Curly's guide was smooth and easy and I found my problem.
Initially, my battery turned out to be bad. Eventhough I bought it just 6 months ago. Now everything checks out, but my rotor is weak (4.0 omhs), but is still charging a 13.8 at 3,000 rpm. So, till I can get a new, or a re-wind, I'll keep it on the 'Tender' between runs.

Thanks again for your 'guide'ance.

Bryan
'79 Yamaha XS 650 SuperMoTracker
'04 KTM 625 SMC
'72 Yamaha 360 MX

[magnang]

Thanks very much for you troubleshooting guide Curly. It's by far the best info on this I've found, and I've see loads as I've been trying to get my bike to Charge since february!!

I'm hoping you or someone else can humor me for a second, I've done all the tests here and have had good results, yet no charging. Hopefully I can find some help, my bike is almost done otherwise

My bike is an points model Rotor/Stator with a solid state regulator / rectifier. I understand the Brushes ground out through the regulator. The brush holder has been un-ground using Nylon screws

- Feeler Guage test: No magnetism

- Regulator Bypass test: My red wire and fuse holder melt, every time!!

- Voltage on the brown wire / brush: Good, less than .3V drop from the ignition switch. The brushes are new from MikesXS. The ground on the regulator / Rectifier gets almost perfect continuity with the Battery Negative.

- Rotor Tests: 5.5OHM between slip rings, no continuity to ground with brushed removed. I DO get continuity to ground with the brushes in and plugged into the regulator, I assume this is normal? The regulator is grounded after all.

- Stator checks: when the engine is at idle I get 0 VAC on all 3 white wires... This is a problem... I do this with the white wires plugged into the reg/rectifier by probing the back and a ground on the motor. Multimeter only does 200VAC...

- Stator check 2: Check the ohm between each white wire: 0.5 between each leg (good)

- Stator check 3: Continuity between each white wire and the ground = No Continuity (good)
Regulator / Rectifiers, I've tried two different Regulator / Rectifiers and the same thing happens with both. Both Pass the 6 Diode test I've seen in my Clymers (each white with red, each white with black).



Any ideas?

[xsleo]

Magnang, Using the points stator with a later model combo reg/rec, yes you need the nylon screws.
Feeler gauge test: no magnetism: no current flow through the rotor. You ohm test indicates a good rotor. This would indicate a wiring fault. To use the combo reg/rec at the brushes you need the nylon screws. They install in the upper left, upper right and lower right positions. If wrong your battery voltage will go to ground. The black wire from the brush you ungrounded is either replaced by a brown wire or just run up and hooked to the brown wire that hooks to the reg/rec.
This is the brush you use when doing the reg bypass test. If the nylon screws are wrong the battery voltage goes to ground and melts your jumper.
Regulator bypass test: Melt your jumper See above.
Rotor test: 5.5 ohms. No continuity to ground. Good. Yes, with brushes installed you will get a ground reading through the regulator.
Stator checks: If the rotor isn't working you will get no ac from the stator. On mine with the stator unplugged and the reg bypass jumper hooked I get About 20 VAC on my white wires.
#2 .5 is ok
#3 Ok
I would check to make sure the brushes have the nylon screws in the right places. With all your results being ok except for the few that point to a bad rotor, yours reads 5.5 ohms should be good.
The brush nylon screws are the only thing that I can think would melt your jumper wire and keep all your good parts from working.

[magnang]

Thanks xsleo,

So you think my brushes are grounding out still? I will confirm that tonight by unplugging the regulator / rectifier and making sure there is no continuity with the ground.

Sounds feasable since I think every component checks out with the OHM tests, it must be the wiring. I did hacked it up since I am not using the stock wiring harness, but I've redone it literraly a half dozen times since february...


I'll let you guys know.