Topic: No charging. New stator / rotor...now too much charge!!! RESOLVED.

[grasscutter]

1982 CB650.  Owned for last 17+ years, finally stopped charging the battery a couple days ago.
Made it home, barely.

Charged battery overnight, so I could test electrical system. 
With full charged battery, it wouldn't charge.  Voltage kept steadily dropping when running @ 4000 rpm.

Did all the wiring, resistance checks via the manual.
Nothing conclusive.  So, thought the stator and/or rotor might be going bad when getting hot.

New rotor and stator installed today. 
Hit the starter, and it fired up instantly.  Was faster than before.
Good, right? 

Put meter on the battery, and see that @ idle its @ 15-15.5v.
@ 4000 rpm its 16-16.5v.

Swapped out a known good voltage regulator from another running CB650 project, and there was no change in the voltage.

According to the book....its supposed to max out @ 14.5v.

So...what do I check now?

**There are 2 ignitors (thats what the manual calls them) right by the battery.  Do they play any part in the charging system?

[onepieceatatime]

1982 CB650.  Owned for last 17+ years, finally stopped charging the battery a couple days ago.
Made it home, barely.

Charged battery overnight, so I could test electrical system. 
With full charged battery, it wouldn't charge.  Voltage kept steadily dropping when running @ 4000 rpm.

Did all the wiring, resistance checks via the manual.
Nothing conclusive.  So, thought the stator and/or rotor might be going bad when getting hot.

New rotor and stator installed today. 
Hit the starter, and it fired up instantly.  Was faster than before.
Good, right? 

Put meter on the battery, and see that @ idle its @ 15-15.5v.
@ 4000 rpm its 16-16.5v.

Swapped out a known good voltage regulator from another running CB650 project, and there was no change in the voltage.

According to the book....its supposed to max out @ 14.5v.

So...what do I check now?

**There are 2 ignitors (thats what the manual calls them) right by the battery.  Do they play any part in the charging system?

If you know the other regulator is definitely good, I would start checking the wiring to the regulator. There may be a problem with dirty connections or high resistance in the wire making the regulator see lower levels than it should. The stators rarely fail, and you may want to swap back to the old to see what happens then. Usually the rotor will fail and short the rectifier/regulator. Were your replacement parts new factory, or aftermarket?

The ignitors are not related to the charging system, they fire the coils for the ignition system.

[grasscutter]

Not spending another 2 hrs swapping a stator back out.  ...Not yet anyways.

New parts from Ricks electronics.  New re-wound rotor and stator.

Good to know about the ignitors.  Didn't think they affected charging...

Voltage on the battery is over 16v!  Hmmm... that's odd.
I've got an older battery in that other CB650 project.  Will swap them out and see what the change is.
Bad battery??

[HondaMan]

More likely: bad grounding somewhere. In particular, look for the big ground cab;e to the engine, remove it and clean it and the engine where it bolts in. Then find the Green wire that connects to the regulator, and track it down to the source. On some of the SOHC4 bikes, this is up under the tank on one of the coils' mount bolts, on others it is up under the seat (to get to the frame).

But...these answers are supposing that the new "rewound" parts you have are appropriately made.   

[Bodi]

There's no way for the alternator to charge - at all, let alone too much - unless the regulator is providing power to the field coil. If there's a ground problem (re HM's advice) then the regulator might not be able to measure the battery voltage and think it's low, it will constantly supply maximum power to the field coil in this situation. You can just measure voltage between the regulator ground (green wire) and power (black wire): if it's very low compared to the actual battery voltage, there's a problem somewhere. You can isolate this by measuring with key ON from regulator green wire terminal to the bike frame: much voltage at all (even 1V) means a bad ground either from the battery or from the harness. From the black wire terminal to battery "+" you should get maybe 1 volt to 2 volts, no more. Lower is better, this shows the harness's voltage drop due to the harness wire resistance (unavoidable) plus harness connectors (these should all be cleaned) and switch contacts (harder to clean).
If you've installed a non-stock regulator, ensure it's the correct type. Some of these are "shunt type" which work the alternator at 100% and waste any excess power, not a good choice for our alternators which are not designed for full output all the time and tend to overheat and fail. Some, for example the DOHC4 ones, work differently from SOHC4 stock and the harness wiring has to be changed slightly to accommodate them.
A stock regulator or aftermarket ones like the Oregon Electric ones designed for our systems should work fine with no mods.

[grasscutter]

Guys.  Guys.  Guys. 

All I can do is shake my head.  (partially in shame).

The key, is in my 2nd post.
(tested battery and it had over 16v!)
Is that even possible?

Sooooo....end result???
My volt meter had a low battery. 
False readings all over the place.
No wonder I couldn't get solid readings when doing the ohm tests, on stator, etc.

Installed new 9v in the volt meter and went through the checks again.
Everything checked out dead on!  Volts not over 15.0 when over 4000 rpm.

Lesson learned, eh?
(side note:  there's a 'low batt' light on my meter too.  Completely overlooked it!)