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Discussion Starter · #1 · (Edited)
Hey Guys,

I am the newish owner of a 1979 cx500 custom with 22k miles. Everything is working but the charging system. I've redone the carbs using Larry's carb book, replaced coils, spark plugs, and new gel cell battery. It's running great besides the battery not charging. At first, I thought it was the stator, but I've tested it and it seems to be okay (according to online numbers anyway). It hates going above 5k rpm's in 5th gear though when the battery goes below 12.3.

Stator Readings with a fully charged battery (12.9v):

1/5 = 121
2/5 = 104
3/5 = 232
4/5 = 128
6/5 = 105
7/5 = 231
9/5 = 382
9/8 = 86

Yellow Wires:
A/B = 1.2
B/C = 1.1
C/A = 1.3

The battery is at 12.3 usually when it is running. Reving does nothing.

Possibly maybe the pickups are gone?

I did replace the rectifier with a used one, but nothing changed. I am doubtful that 2 stators were faulty, but you never know.

Right now I just throw it on a battery tender when I get home at night, but that's not really a great permanent solution :)

Any ideas on what I should do next would be greatly appreciated!


Update:
All 3 yellow stator wires grounded to the frame measue 00.1 resistence in ohms, which is what the mulitmeter reads before starting. So I am assuming it's really zero.
 

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Have you tried doing an insulation breakdown on the stator? The insulation on the wires inside the engine of these older machines likes to break down over time. Check the resistance from each of the yellow wires to ground. It should read OL. I don't believe there would be a problem with the reg/rec as that just prevents overcharging and turns AC to DC voltage.
 

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Hi Luke,
There is a similar post to this "Charging Question" that has this posted on it as something to check, i have copied and pasted it here for you to check

there should be infinite resistance between any of the yellow wires and ground and the resistance between any 2 yellow wires should be about 0.5 ohms.

NOTE: Before measuring a resistance that low you should always touch the meter's leads together and note the reading (ideally zero but sometimes the test leads themselves can have a measurable resistance), then subtract that value from subsequent readings to determine the actual resistance.

Worth a check
 

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Discussion Starter · #4 ·
Have you tried doing an insulation breakdown on the stator? The insulation on the wires inside the engine of these older machines likes to break down over time. Check the resistance from each of the yellow wires to ground. It should read OL. I don't believe there would be a problem with the reg/rec as that just prevents overcharging and turns AC to DC voltage.
Well the three yellows wires read 1.2,1.1, & 1.3 when grounded to the battery. Does that mean she's shot?
 

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Hi Luke Holloway,
To test for resistance you need to apply the following,
Remove the battery. ...Turn the meter selector dial to one of the resistance settings.Touch the meter leads to the two points in the circuit for which you wish to measure resistance. I wouldn't have thought you would need to put one of the leads on the ground of the battery, the battery should really be disconnected from the circuit otherwise you will get false readings, with the battery on the bike disconnected put one of the leads of the metre on the one yellow and the other metre lead on the bike frame, you should get an "OL" reading on the display meaning, "No continuity" or "Open loop". Do this for the other yellow wires etc
Let us know how you get on :)
 

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Discussion Starter · #6 ·
Hi Luke Holloway,
To test for resistance you need to apply the following,
Remove the battery. ...Turn the meter selector dial to one of the resistance settings.Touch the meter leads to the two points in the circuit for which you wish to measure resistance. I wouldn't have thought you would need to put one of the leads on the ground of the battery, the battery should really be disconnected from the circuit otherwise you will get false readings, with the battery on the bike disconnected put one of the leads of the metre on the one yellow and the other metre lead on the bike frame, you should get an "OL" reading on the display meaning, "No continuity" or "Open loop". Do this for the other yellow wires etc

Oh, I didn't realize that. Does that go the same for the other resistance tests I did on the stator also (removing the battery for accurate readings)?
 
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If you have unplugged the stator connection then the battery will have no effect on your resistance readings. These readings need to be done with the connections unplugged.
If the charging coils of your stator are functioning properly you should see voltages in the 13-14 volt range when the engine is running. I think that you may be looking at a stator replacement
 

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Yes mate, if the battery is in the circuit then a false or totally different reading can be seen.
The resistance value you get will determine whether the part you are testing is faulty or doing the job it is supposed to be doing, by having the battery in the circuit this will change that value.
"Resistance is the measure of difficulty electrons have in flowing through a particular object. It is similar to the friction an object experiences when moving or being moved across a surface. Resistance is measured in ohms; 1 ohm is equal to 1 volt of electrical difference per 1 ampere of current."
Good luck
 

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Luke disconnecting the stator connectors does remove the battery as far as the resistance tests are concerned.
 

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Discussion Starter · #10 ·
Yes mate, if the battery is in the circuit then a false or totally different reading can be seen.
The resistance value you get will determine whether the part you are testing is faulty or doing the job it is supposed to be doing, by having the battery in the circuit this will change that value.
"Resistance is the measure of difficulty electrons have in flowing through a particular object. It is similar to the friction an object experiences when moving or being moved across a surface. Resistance is measured in ohms; 1 ohm is equal to 1 volt of electrical difference per 1 ampere of current."
Good luck
Okay. So grounded to the frame I get 00.1 on all three yellow wires, which is what I get touching the multimeter probs to themselves, so I assuming this means my stator passes this part of the test?
 
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to ground should be Open Loop{infinite resistance}

same as with probes not touching.
 

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Discussion Starter · #12 ·
to ground should be Open Loop{infinite resistance}

same as with probes not touching.
So are you saying that this is where my problems lies?
 

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Luke in your first post you give these readings;
Yellow Wires:
A/B = 1.2
B/C = 1.1
C/A = 1.3
In post 4 you say "Well the three yellows wires read 1.2,1.1, & 1.3 when grounded to the battery." Are these the same numbers? If so you need to measure the resistance from each yellow wire to ground. You want to see an open circuit, the same as if the probes of your meter were not touching anything.
By the way have you been following this guide? https://motofaction.org/motorcycles/honda-cx-gl/how-to-check-test-stator-honda-cx500/
 

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Discussion Starter · #14 ·

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It looks like the winding's are shorted to ground,

or core of the field this is bad.
 

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Discussion Starter · #16 ·
Okay, so can that be fixed or do I need to go ahead and just order a new stator?
 

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When you open the case you may be able to find where the windings are shorting to ground and repair. For example the three yellow wires may have chafed and be touching metal. I wouldn't hold out much hope though. I fear that you will need a new stator.
 

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Discussion Starter · #18 ·
When you open the case you may be able to find where the windings are shorting to ground and repair. For example, the three yellow wires may have chafed and be touching metal. I wouldn't hold out much hope though. I fear that you will need a new stator.
Okay. Well, it looks like I got my Saturday all cut out for me! One last question, does anyone have any horror stories with the mister electrical stators? I've read mixed reviews but the low price of $59 makes me raise my eyebrows a bit compared to the other $180 stators floating around the web.

Specifically this one here: Generator Stator For Honda CX 500 1978 1979 1980 1981 | eBay
 

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At that price I'd be takin my chances.

maybe order 2 (if you have the cash)

Good thing about feebay is you can return

for an extended period of time even if

u just don't like the way it looks.

From what I've heard they work but the but varies

from the stock "specs".

(when readings are taken for troubleshooting)

for the ignition coils.

Unless they are using other/different coils

than before.


Oh..................and it won't be this coming

saturday doncha hate waitin.
 

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Discussion Starter · #20 ·
At that price I'd be takin my chances.

maybe order 2 (if you have the cash)

Good thing about feebay is you can return

for an extended period of time even if

u just don't like the way it looks.

From what I've heard they work but the but varies

from the stock "specs".

(when readings are taken for troubleshooting)

for the ignition coils.

Unless they are using other/different coils

than before.


Oh..................and it won't be this coming

saturday doncha hate waitin.
Haha, yup It just hit me that I won't have the part yet!

Excellent. Thanks so much for the help! I'll will let yall know how it goes.
 
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