1970 XS1 Not Charging

[redbug2]

Hello,

I have a 1970 XS1 that's not charging enough.

Everything is pretty much stock. Battery Voltage is around 12 volts. When it runs I'm down in the 11 volt range. Thought it was a rectifier so I created a new one, no difference.

I also have an XS2. I have tried swapping the XS2 regulator, voltage regulator. No difference. Exchanged the rectifier from the xs2, no difference.

I ran all of the tests on the components via the clymer manual that I have. All tests on the voltage regulator were within range.

Saw some tests on youtube. The energized stater will pull a wrench in when energized. The voltage to the outside brush on the stater is around 7.5 volts.

I have the cap to the voltage regulator off and have moved the points up and down to get maybe 1/2 a volt difference. I have tried adjusting the set screw and nothing has really changed.

Any other tests or changes you could recommend will be welcome.

Regards,

redbug2

 

[Ceed Klumper]

If all the components check out then it must be in the wiring/cables, I would think?

 

[redbug2]

Yes, probably has some wiring done wrong. I'll be double checking that next.

 

[motormike]

Brushes ?

 

[gggGary]

pull the stator and measure the rotor across the slip rings should be 5 to 6 ohms, less than 5 ohms is a (common) problem.

 

[peanut]

View attachment 126266

gorgeous bike !



redbug2

you should be seeing 12v+ at both the outer stator brush and the outer rotor ring so there is a considerable voltage drop somewhere between the battery and your stator brush.
I'm not familiar with the 72 electrical circuits and cannot find a schematic but I'd imagine that you have a bad connection somewhere with a high resistance so make sure that you have 12v+ at the battery then check your regulator, rectifier, stator , fuse , and battery connectors , stator brushes and of course your ground connections.

 

[redbug2]

I checked the ohms on the 70 xs1 stator and the reading was .5 ohms, very low. The 1973 parts bike that I have showed that it's stator is reading 6 ohms. So, looks the Ohm meter is good and stator in the xs1 is bad.

On to removal of stators.

Thanks for the advise.

 

[peanut]

5 ohms on the rotor is fine ...its not exactly 6 ohms thats required ...there is a tolerance + or - .

Its the Rotor that you should be checking for resistance of the coil winding not the stator.
did you watch the video ? it explains exactly how the charging system works and how to test the rotor and stator

This is your problem

The voltage to the outside brush on the stater is around 7.5 volts.

 

[redbug2]

Sorry, did not watch the video first. Now I did. Had my terms wrong. Please forgive me.

To clarify, XS1 Rotor is giving me .5 ohms (point five). Not Five ohms.

 

[peanut]

Sorry, did not watch the video first. Now I did. Had my terms wrong. Please forgive me.

To clarify, XS1 Rotor is giving me .5 ohms (point five). Not Five ohms.

no worries redbug thats ok ......many do get that wrong which is why I mention it in the video.
If the resistance in the coil is only half an ohm then your rotor is fubar I'm afraid

Just as a check you might set your multimeter to continuity and put the probes together and check that the meter is zeroed You should here a whistle or beep if you are on the correct setting. Most digital meters are self zeroing but the leads can develop some resistance, giving you false readings.My leads have a 0.7 ohm resistance so I have to add that to all my tests.

So have you found out why you only have 7.5 volts at the outer brush yet ? I take it that you remove the wire from the outer stator brush connector before testing the voltage on the wire yes ?

 

[redbug2]

After replacing 1970 rotor with a 1973 version the alternator was putting out considerably more voltage. I still have to adjust the voltage regulator.

 

[peanut]

well done ...that was an easy fix . You can buy LED charging indicators on ebay which give you an indication of the charging status . Many owners fit a Digital voltmeter which is probably a better option
This is a really neat solution but cheap external gauges work just as well
http://www.xs650.com/threads/77-79-standard-in-dash-voltmeter.49689/