Topic: Stator Options

[Vintageguy]

1978 CB750F. What's everybody using for replacement stators these days? Mine died recently (putting out 11+ volts). Have seen some from "You-Know-Where" recently, but don't really trust them. Don't like to purchase used electrical equipment if I can avoid it. What are the options these days. Thank you for any/all responses.

[bryanj]

Rare for stator to go bad, more often a bad connector or if a combined reg reg the electrinic reg

[Vintageguy]

Isn't stator supposed to put out more than 11 volts?

[MauiK3]

If is really the stator, Yamiya has them.

[Vintageguy]

Again. Isn't stator supposed to put through more than 11 volts? Thank you.

[Vintageguy]

Thanks.

[scottly]

Again. Isn't stator supposed to put through more than 11 volts? Thank you.

The stator is only one part of the charging system, which includes the regulator, the field coil, the rotor, the stator, and the rectifier. From your earlier thread, your regulator tested OK, but the field coil failed the magnetism test.
http://forums.sohc4.net/index.php/topic,206208.0.html

[PeWe]

How to kill the stator with the field coil except for cutting a wire or 2?

Clean all connectors. Honda shop manual has a chapter for the charging system where all parts and wires are shown.

CB750 has a good one. More amps would be fine.

[bryanj]

Yes it will put out 60 volts ac when disconnected and you check across the 3 pairs of yellow cables.

There is a complete charging system check in the Honda workshop manual.

Again in over 40 years i have only seen 1 bad stator EXCEPT for ones damaged physically in accidents.

Bad charging is 95% usually bad connections or failed aftermarket combined reg/rec

[Vintageguy]

Thank you for the responses. This system is 100% OEM in all respects. Yes, the regulator checked out with 12+ in and out. The field coil did fail the magnetic test as suggested. In addition, field coil only put out 11 volts. Can I assume, therefore, that my field coil has failed? Thank you again. 

[bryanj]

Nope, you need to check all the connectors, especially the bullets under the sprocket cover and do the resistance checks in the Manual.

Electrical repair on Hondas does not work by throwings parts at it but by carefull and methodical testing

[newday777]

Thank you for the responses. This system is 100% OEM in all respects. Yes, the regulator checked out with 12+ in and out. The field coil did fail the magnetic test as suggested. In addition, field coil only put out 11 volts. Can I assume, therefore, that my field coil has failed? Thank you again.

You have not told how you tested any of your charging parts and gotten the volts and where at you got the readings measurements at or if you cleaned any of the different connectors, in either of your threads. No one can see what exactly you have done or not done.

[bryanj]

This sort of post is why i no longer try to help over the net, people will not do only the test asked for but wander off on a tangent doing other things.
To sort an electrical problem you need to be methodical and focused but mostly LISTEN

[HondaMan]

Isn't stator supposed to put out more than 11 volts?

One of the most common "alternator fails" I have seen since 2005 aren't the alternators at all. It is the cheaper batteries made in China, using recycled lead. They only last about 5-6 months from new before their voltage falls below 12.0 volts, dragging the entire electrical system down with them. In the CB500/550 bikes these are a sheer disaster, while the larger CB750 alternator might net a year of use from the battery.

Prior to the Chinese junk-battery invasion, most failures were (and still are) the 5 bullet connectors to the alternator under the engine's left side cover (near the countersprocket) - 2 to the filed coil and 3 to the alternator. These little plugs were zinc-plated in the 1970s, which fell off of them (used or not) around 1990 or so. The resulting grit is a resistor and heats up the plug: the jackets over them are usually burnt dark in testimony. You can buy a new 'sub harness' at PartsNmore that has the 8-circuit plug on one end and good brass connectors on the other: you can get new brass connectors (3.5mm size) for the alternator & field coil from VintageConnections.com, along with a most-excellent crimper (I have 2 of them).

[seanbarney41]

Also, one quick easy fix...have you disturbed the cover for the regulator and then plugged the red, green and white wires back in correctly?  One time I was cleaning and polishing the reg. cover and got it installed wrong,  or  the wrong one or something...so tyhat the order of the 3 wires was indicated different by the color markings on the cover.  If you get any one of these wrong, you get the symptoms you have described.  This took several hours to diagnose. I had been going through my collection of spare regilators and found that there are at least a few different layouts, but the covers all interchange and the covers can also reverse!

[newday777]

Also, one quick easy fix...have you disturbed the cover for the regulator and then plugged the red, green and white wires back in correctly?  One time I was cleaning and polishing the reg. cover and got it installed wrong,  or  the wrong one or something...so tyhat the order of the 3 wires was indicated different by the color markings on the cover.  If you get any one of these wrong, you get the symptoms you have described.  This took several hours to diagnose. I had been going through my collection of spare regilators and found that there are at least a few different layouts, but the covers all interchange and the covers can also reverse!

Red? Don't you mean Black? Black, Green and White

But definitely an interesting observation to check.
Different layouts, all your regulators are from 750s?

That's why pictures are so important to take before disassembling.

[Vintageguy]

Fixed it myself. Thank you for all the helpful comments. To the critical and impatient responders, consider leaving the Forum if you can't provide helpful and patient input to novice bike owners/riders/fixers. Perhaps you've just had enough and are over it. Think about it.

[seanbarney41]

Also, one quick easy fix...have you disturbed the cover for the regulator and then plugged the red, green and white wires back in correctly?  One time I was cleaning and polishing the reg. cover and got it installed wrong,  or  the wrong one or something...so tyhat the order of the 3 wires was indicated different by the color markings on the cover.  If you get any one of these wrong, you get the symptoms you have described.  This took several hours to diagnose. I had been going through my collection of spare regilators and found that there are at least a few different layouts, but the covers all interchange and the covers can also reverse!

Red? Don't you mean Black? Black, Green and White

But definitely an interesting observation to check.
Different layouts, all your regulators are from 750s?

That's why pictures are so important to take before disassembling.

yeah, my bad...black not red.   And yeah, I probably have a stash of 6 regulators and most are from cb750, maybe at most 2 could be 550?  I am pretty sure there were at least 3 different model numbers amongst the collection all with slight variation on which way the cover mounted and/or different directions the wiring leads faced.  Also this was a K7 bike which typically has sneaky subtle changes from Honda that few have caught. 

[seanbarney41]

Fixed it myself. Thank you for all the helpful comments. To the critical and impatient responders, consider leaving the Forum if you can't provide helpful and patient input to novice bike owners/riders/fixers. Perhaps you've just had enough and are over it. Think about it.

...or? YOU could post what you had to do to fix the problem...then maybe these novice bike owners/fixers/riders could solve their problems without disturbing cranky old knowledgeable bike owners/fixers/riders.  Ar least one electrical mystery laid to rest...

But hey, you just have to understand.  These kinds of electrical problems often cannot be seen, even with pictures, so communication has to be clear on both ends and nobody wants to read this meticulous stuff any more times than they have to.  No one meant you any insult. 

[PeWe]

No answer about the problem?

[bryanj]

Vintageguy, if you cant, or wont answer the questions asked or keep asking the same question repeatedly without listening or trying the tests suggested dont suggest that people with decades of fault finding and maintaiance are wrong