Topic: The Ever-Popular CB650 bad charging 'issue', formerly hot start 'issue'

[martino1972]

you sure you keep it above 3000rpm,kit...?   

[MikeB]

Hey kit
just reread this post again , are you bald yet

FWIT
I had to replace the rotor on my 82Nighthawk
when i got the bike(not running) the stator was replace by the po.
but he still could not get the bike to run (prob. was bad pickup coil and bad ign.coil)
after fixing that.

my rotor (also on the low side 4.2 ohm),stator, and r/r tested ok ,It seemed to be charging but after running the engine to operating temps and trying to set the carbs it was not charging like it should have (don't remember what it dropped to  but it wasn't in the 13- 14v range)

I replaced the rotor thinking this was the weak link (from this forum and others with these bikes)
and that fixed it
I think the rotor had some of the winding shorting together when it would heat up, lowering the
res. in the windings

if I'm following correctly, what TT has been saying 
if this res. goes down in the rotor, it will try to draw more current from the battery to
maintain the same output from the R/R or will it weaken the magnetic field that the stator sees or both 

I know in a electrical circuit if you lower res. and the voltage stays the same current will increase

God I hope this made sense
if this is NOT HELPING than just yell at me and I will shut up

I truly understand your frustration!

http://www.twtex.com/forums/showthread.php?t=32255&highlight=nighthawk


However, I also trust you will be able to figure it out.


God bless,

Lee

Lee
how far could you ride your bike with the charging system unhooked 
and did your bike start right back up after riding this distance 

Kit this might be a good test to see if its your charging system or your starter that's depleting
you battery 
unplug charging system see if you still have this prob. after riding same amount of time as before

if you do still have prob. maybe starter, lights or  battery
maybe also try running with lights unplugged 

if do not still have prob. than would have to be charging system 
at least that should isolate somewhat

After trouble shooting electrical problems in residential and commercial buildings for 20yr
I feel your pain 
also feel you WILL solve this prob.


Wish I could be of more help but wiring in bikes is something I'm just now getting into.

[TwoTired]

if I'm following correctly, what TT has been saying 
if this res. goes down in the rotor, it will try to draw more current from the battery to
maintain the same output from the R/R or will it weaken the magnetic field that the stator sees or both 

That's the gist of it, pretty much.
Lower resistance will draw more power/current given the same voltage potential applied.
The usual cause of lower resistance is shorted windings.  This changes the effective wire length (hence the term "short").  And, less wire length reduces the magnetic field strength.  Ergo, both reduced power out from the stator and more power consumption by the rotor, stealing energy meant for battery recharge or other bike electrical consumption.

The rotor is a spinning mass subject to both heat and centrifugal force where the windings want to fly out of captivity.  The heat softens the wire insulation and the centrifugal force/ running vibration mashes the insulation between wires.  When the insulation achieves enough displacement, the wires "short".  Exactly where they short determines the final resistance.

But, I still want to see the battery load test results.  Beware that auto battery testers may apply more load on the car batteries than should be applied to MC batteries.   
I found these for those interested.  Looks like the first one would be good enough for MC batteries and checking starter motor draw.  But, all should work for load testing both battery and charging system.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=93784
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=90636
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=91129

Hey Kit, bring the bike by my garage. I can probably sort out the problem in a few minutes. 

Cheers,

[Hush]

I'm for that TT, load that sucker on a freight plane Kit and send it to Dr TT for a check-up.

[leekellerking]

FWIT
God I hope this made sense
if this is NOT HELPING than just yell at me and I will shut up

I feel the same way.  I do not want to confuse the matter at hand with my war stories if they are not helping.

However,on thing I have learned is that with old bikes like ours, it may not be any ONE thing that is causing the problem, but a combination of things.  Therefore, my mumblings may help, even though the symptoms Kit is experiencing are not exactly the same.

For instance, before I cleaned/replace the connectors and such, I think my bike was also not charging to snuff. 

I truly understand your frustration!

http://www.twtex.com/forums/showthread.php?t=32255&highlight=nighthawk


However, I also trust you will be able to figure it out.


God bless,

Lee

Lee
how far could you ride your bike with the charging system unhooked 
and did your bike start right back up after riding this distance 

[/quote]

I could ride to work and back (say, 22 miles round trip) and have a little juice left.  My bike had no starting problems if there was juice.  I have, however, had one or two instance of the "hot starting" thing but it went away.

BTW, I have had my blinkers off the bike until a couple of days ago.  In Texas, you don't have to have turn signals, but if they are on the bike they have to work.  I cheated and pulled them off the bike to get it inspected.  I am now troubleshooting why they won't blink.

I mention this because my bike does not seem to turn the light "green" on the battery tender as soon as it did.

UPDATE

I went outside and the light is still yellow after sitting on charge all night.  Of course, this is the Batteries Plus battery that has been completely discharged several times and that was further abused when I had the charging system unhooked, so YMMV.


Lee

[MosquitoJones]

Mosquito Jones -- have you tried removing the cover to the air filter and using large washers to hold the filter in?  It made a world of difference for my 82 CB650SC.

Before I did that, it would lose power and slow down to 60 to 65 mph on the freeway.  Now it doesn't.

Lee

Yep.  It did help quite a bit with power overall at high speeds.  If this weather would ever get back to normal (a week ago it was 70 degrees and today it's snowing again - but that didn't stop me from riding to work  ) I plan on trying to clean out the vent hole in the gas cap to ensure I'm not getting vapor lock at high vacuum.  It's not just that it slows down, it will totally choke out and die on occasion.  Let it sit for a minute and it gets right back to normal. 

[Frankenkit]

Ok, the plan for today is to really just start isolating the main issues here:
take the battery to the local shop to get load tested,
fit the new starter solenoid (and later see how low battery voltage goes when cranking)
hook everything up and see what the rotor / stator do (a'la Pinhead's testing)
(now, do I disconnect the entire RR from the harness when doing that test so I don't fry anything? By 'that test' I mean using gator clips to attach the black and white brush wires to the negative and positive battery cables, accordingly)  If that doesn't prove I have a shot rotor, I'm going to go ahead and check through the stator, and just make sure it's making +50 vAC at each coil.
By this point I'm still pretty sure the stator's ok, but I'm not positive, so I'm just trying to rule it out.

From what I'm gathering we're still looking at an overlarge draw to the rotor caused by decreased resistance, as well as a potential contribution from the starter solenoid because it may not be triggering with the standard amount of juice anymore, or relaying enough power.

Before even starting the bike I'm going to test for parasitic draw and also test how much power is going to the bike just having it 'on' and running, to see what kind of draw we're experiencing.

One question.

If my system typically requires the battery to provide the juice necessary to create the electromagnetic condition of the rotor, could I still run the bike sans battery hookup for a period of time to hook up the gator clips and see where that drain is at?  The way I'm envisioning it is that the electromagnet sucks a small amt of battery power to (hopefully) produce a much greater amount in the alternator, which in turn powers the bike and recharges the battery.  If I disconnect the battery, will it cease to produce power/kill spark/shut down the bike?

[MikeB]

The way I'm envisioning it is that the electromagnet sucks a small amt of battery power to (hopefully) produce a much greater amount in the alternator, which in turn powers the bike and recharges the battery. 

that's the way I understand it 
(why not just use a permanent magnet )

  If I disconnect the battery, will it cease to produce power/kill spark/shut down the bike?

Yes it will cease to run
battery supplies power to CDI units (capacitors ?)
which are triggered by pickup coils to fire the ign.coils (I believe this is the flow  )

In any case the bike will not run without the battery

[leekellerking]

Ok, the plan for today is to really just start isolating the main issues here:
take the battery to the local shop to get load tested,
fit the new starter solenoid (and later see how low battery voltage goes when cranking)
hook everything up and see what the rotor / stator do (a'la Pinhead's testing)

Hmmm.  I'm not sure about that process.  Without the rectifier, the output will be AC and your battery is DC.  I would (at the least) place an inline fuse in the circuit to minimise the chance of damaging your battery.

[MikeB]

So my question is... if we find the rotor to be at fault, do we simply have it rebuilt? I think that would be better and easier than trying to get an NOS one. I'm actually thinking it's the rotor but I'm not ruling out a 2nd culprit since the electrics are so old.

Mickey if you find it to be the rotor
I got mine from Denise Kirk
http://www.denniskirk.com/1/1/300993-electrosport-industries-rotor-esf901.html
they are manufactured by Electrosport industries
http://www.electrosport.com/products/product-detail-409.php

[leekellerking]

I have heard ungood things about the Electrotex rotors.  I went with Custom Rewind as recommended by my electrical guru, Tony Weeks.  I think the cost was about the same, but I figured I'd go with the one recommended by the neutral party.


YMMV.

Lee

So my question is... if we find the rotor to be at fault, do we simply have it rebuilt? I think that would be better and easier than trying to get an NOS one. I'm actually thinking it's the rotor but I'm not ruling out a 2nd culprit since the electrics are so old.

Mickey if you find it to be the rotor
I got mine from Denise Kirk
http://www.denniskirk.com/1/1/300993-electrosport-industries-rotor-esf901.html
they are manufactured by Electrosport industries
http://www.electrosport.com/products/product-detail-409.php

[TwoTired]

A battery static voltage of 12.4V equates to a battery charge state of about 80%.
The bike should have no trouble starting with that voltage from a good battery (one that is able to deliver high amperage).

The data point of it going below 9V during starter engagement, tells me more current is being demanded from the battery than it is able to provide.  Since we don't know how much current is being demanded in THIS BIKE, we don't know if the battery is worn out, or if the starter motor is drawing too much power. If you had a 200 amp current meter you could further isolate cause.
The fact that the voltage drops as much as it does, tends to eliminate the solenoid as a cause, because if this was failing, the current draw would be restricted from the battery, and voltage wouldn't drop so deeply.  It appears to be transferring the current load from starting motor to the battery, as is its job.

So, the options are:
Load test battery to see if it is capable of high current loads.
Or, swap in a battery that is known to deliver high current loads.
Measure the actual current draw of the starter motor, to see if it is within specifications.

Charging system.

The R/R is a combined unit with two functions.  Control or tame the awesome power of the alternator, and to take that awesome output power that is AC and convert it to DC.  The R/R has a single plug connecting it to the Alternator.  Across this plug both functions occur.

To get power from alternator to battery the three yellow wires MUST be connected.

To bypass the regulator function in the R/R. (that which controls the alternator awesomeness)  You must withdraw pins from that single R/R connector (White and Black wires), so YOU can be the regulator when you attach these wires to the battery directly, while allowing alternator connection to the rectifier portion (yellow wires).
Your job as regulator is limited to let-the-fury-that-is-alternator-be-released-to-the battery (wires connected to battery), or let-the-alternator-play-dead White and black wire disconnected from the battery, you're call.  All the while being mindful that full alternator fury can only happen when the engine is revved up AND connected to the battery.

Let is be said that with the data so far provided, I don't think the R/R has a problem at this point.  But, you are free to divert attention toward whatever whim you wish.

I don't agree with the holistic approach that bikes with similar symptoms must have the same root cause of those symptoms.  There are too many instances where different causes result in quite similar descriptions of symptoms.  Too rich or too lean is once such instance where the bike "bogs".   Electrical systems can easily yield identical symptoms with different root causes of failure.

Cheers,

[MikeB]

I have heard ungood things about the Electrotex rotors.  I went with Custom Rewind as recommended by my electrical guru, Tony Weeks.  I think the cost was about the same, but I figured I'd go with the one recommended by the neutral party.


YMMV.

Lee

So my question is... if we find the rotor to be at fault, do we simply have it rebuilt? I think that would be better and easier than trying to get an NOS one. I'm actually thinking it's the rotor but I'm not ruling out a 2nd culprit since the electrics are so old.

Mickey if you find it to be the rotor
I got mine from Denise Kirk
http://www.denniskirk.com/1/1/300993-electrosport-industries-rotor-esf901.html
they are manufactured by Electrosport industries
http://www.electrosport.com/products/product-detail-409.php

Well I didn't want to here that 

Lee did you mean to say Electrotex because they used to sell R/R and electrical componets (but think they went out of bussiness)

got mine from Electrosport Ind.

[leekellerking]

Sorry.  I meant Electrosport, I think.   

I could be wrong. 

Just ask my wife! 


Lee

I have heard ungood things about the Electrotex rotors.  I went with Custom Rewind as recommended by my electrical guru, Tony Weeks.  I think the cost was about the same, but I figured I'd go with the one recommended by the neutral party.


YMMV.

Lee

So my question is... if we find the rotor to be at fault, do we simply have it rebuilt? I think that would be better and easier than trying to get an NOS one. I'm actually thinking it's the rotor but I'm not ruling out a 2nd culprit since the electrics are so old.

Mickey if you find it to be the rotor
I got mine from Denise Kirk
http://www.denniskirk.com/1/1/300993-electrosport-industries-rotor-esf901.html
they are manufactured by Electrosport industries
http://www.electrosport.com/products/product-detail-409.php

Well I didn't want to here that 

Lee did you mean to say Electrotex because they used to sell R/R and electrical componets (but think they went out of bussiness)

got mine from Electrosport Ind.

[Frankenkit]

Well after fiddling all morning, I need to go take the battery to get tested.  
I did find something interesting.  With the neg. cable detached from the battery, and the bike off, no key in it or anything, there was still a draw, somewhere, between the cable and the negative terminal, of .55 vDC.  I went through and systematically removed all the fuses  to see if there was a difference (to see if I could remove the source of the draw) and was unable to do so. Is that normal?  Did I do this wrong, and was I supposed to have the meter on the positive batt. terminal?

either way, it looked like a drain to me.  
TT i haven't wasted time yet on the other testing, just spent some time putting everything back together and polishing my slip rings with 1500 paper to ensure better contact.

Ok, heading out to get loaded load tested and a couple 30 fuses.  Lee, thanks for the wiring diagram help. Since it came with two 20 fuses and I need 30s anyway, I plugged it in the way it was originally, out of curiosity, blew the fuse, then switched them around the way you said, and it was good.

[TwoTired]

Kit, voltage is potential, not a power in and of itself.  Using a water analogy, voltage is like the pressure of water in a pipe.  The pressure may exist without any flow.  Like water, voltage just sits there until current flows. 
Electrical current is like the actual flow of water.  Water may flow at different rates as well as under different pressures conditions.
The third piece of the basic puzzle is resistance to flow.  For water it is similar to putting a valve in the path of the water flow.  Resistance is like that valve, it may be off, on, or somewhere in between.

When you disconnect the battery, you stop all current (flow) from the battery.  A meter set to measure voltage potential only notes the difference between the two probe leads.  Due to meter operating principles, there can be some small amount of current flowing through the voltmeter itself to connect the two probes, but it is in no way accurate to expect that flow through the meter, to be equivalent to a direct connection of cable to battery post.
If you suspect there is an actual current drain with the Key switch off.  You need to insert an Ammeter, not a voltmeter, between battery post and battery cable.  This will tell you if there is a significant amount of energy flowing through the meter, indicating a constant drain on the battery.

Be sure to note what currents your multimeter is capable of measuring.  And don't try to force more through it that it is capable of transferring.  For example, don't try to push the stater motor draw of 200-100 Amp through a meter that can only measure 10 or 20 amps, or something inside the meter will likely melt.

Cheers,

[Frankenkit]

Oh, thanks for the clarification, TT.

Well, the stealership has renewed my complete distrust in them.

I took the battery off the trickle charger and it read 13v.  It sat about 20 minutes beforr I got it to the shop to load test it.

At that point, it read 11.9, but produced normal amperage. They said it was just fine.  I said "Uh, no, it's not. It JUST came off the charger and is now completely dischrged, and you're saying it's fine? "
the  guy said "no, full charge is, like, 12.1."
I said "ok. Thanks, bye." took my battery + left. good thing that was free.

Went to batteries plus and told them what was up.  he tested it in front of me.  full 170 amps, but batt read 12.4 to them.  They're going to keep it a bit to charge it all the way and load test again, just to see what's really going on here.

no battery = no more tests for me today, which is ok because my cold's getting nasty and I need sleep.

[Hush]

"Here endeth the lesson" for today anyway--tune in again same station same Bat channel for more exciting electrifying developments as Kit valiantly goes where no man is brave enough to go!

[Frankenkit]

Just some wonderment since I can't actually do anything (and this dayquil has me thinking in exciting new directions ) TT, would it be a good idea to test the amperage the bike's charging system is putting out vs. the voltage? (using your volume vs. pressure water analogy) would it be possible my bike is putting out great voltage but at insufficient amps? 

Page 16-4 of my honda service manual spouts exaggerated lies about my system.
"Specifications"
AC generator:
1500 rpm: 6.5A min.
5000 rpm: 18A min.
Initial charging: 1650 rpm
...but how many volts at that amperage? or do they think it doesn't matter because the regulator should bring it down to 14.8 no matter what?

[Hush]

You are starting to speak a totally foreign language Kit, some form of electronic geek-speak obviously a derivative of TTish!

[Pinhead]

Just some wonderment since I can't actually do anything (and this dayquil has me thinking in exciting new directions ) TT, would it be a good idea to test the amperage the bike's charging system is putting out vs. the voltage? (using your volume vs. pressure water analogy) would it be possible my bike is putting out great voltage but at insufficient amps? 

Page 16-4 of my honda service manual spouts exaggerated lies about my system.
"Specifications"
AC generator:
1500 rpm: 6.5A min.
5000 rpm: 18A min.
Initial charging: 1650 rpm
...but how many volts at that amperage? or do they think it doesn't matter because the regulator should bring it down to 14.8 no matter what?

The voltage determines how many amps will be drawn. If your charging voltage is steady at 14.4v, that means the alternator is producing enough amps in order to run everything. What happens when there is too great a load for the alternator to produce enough amps, the voltage will drop.

[MikeB]

Just some wonderment since I can't actually do anything (and this dayquil has me thinking in exciting new directions ) TT, would it be a good idea to test the amperage the bike's charging system is putting out vs. the voltage? (using your volume vs. pressure water analogy) would it be possible my bike is putting out great voltage but at insufficient amps? 

Page 16-4 of my honda service manual spouts exaggerated lies about my system.
"Specifications"
AC generator:
1500 rpm: 6.5A min.
5000 rpm: 18A min.
Initial charging: 1650 rpm
...but how many volts at that amperage? or do they think it doesn't matter because the regulator should bring it down to 14.8 no matter what?

The voltage determines how many amps will be drawn. If your charging voltage is steady at 14.4v, that means the alternator is producing enough amps in order to run everything. What happens when there is too great a load for the alternator to produce enough amps, the voltage will drop.

Pinhead ,TT or anyone
is the regulator there to regulate the voltage into the rotor or to reg. the V to the battery from the alt.

[Pinhead]

The regulator regulates the voltage coming out of the stator/alternator (and therefore into the battery) by regulating the voltage into the rotor/field coil.

[TwoTired]

Just some wonderment since I can't actually do anything (and this dayquil has me thinking in exciting new directions ) TT, would it be a good idea to test the amperage the bike's charging system is putting out vs. the voltage? (using your volume vs. pressure water analogy) would it be possible my bike is putting out great voltage but at insufficient amps? 

Page 16-4 of my honda service manual spouts exaggerated lies about my system.
"Specifications"
AC generator:
1500 rpm: 6.5A min.
5000 rpm: 18A min.
Initial charging: 1650 rpm
...but how many volts at that amperage? or do they think it doesn't matter because the regulator should bring it down to 14.8 no matter what?

Thats a good question.
The charging system specs in the book assume a good fully charged battery. A fully charged battery is about 12.6 to 12.8 V.

What the spec tells me is that the alternator isn't expect to put out more power than the bike normally consumes until it is spinning at 1650 RPM, excluding battery recharging. At that RPM, it has to be making more voltage than 12.8V, in order to charge the battery.  In order to take a charge, the battery must receive a higher voltage than it would have statically with no load.

If the regulator is doing its job correctly, it will not allow the alternator to make the battery voltage higher than 14.5V,  with 14.8v an upper tolerance limit.  At these maintained voltages, the battery should be out-gassing freely (looks like it is boiling).  And, higher voltages will induce battery heating, as well.  The gassing is liberated hydrogen and oxygen, a highly flammable combination when an ignition source is present.  Something to note and respect.

What bothers me about your earlier test numbers, was that even a partially depleted battery should take some time to come up to peak voltage while it is being charged.  You shouldn't be able to put all the charge it has lost back instantaneously.  The chemistry needs time to do it's thing.

The 170 amp load is a decent test for the battery.  It would be useful to know what the battery voltage was maintained at under that 170 amp load.

If we knew the voltage did not dip below 10.5 v at that test load, then your starter would be suspect of exceeding that amperage when the voltage was seen to dip below 9V.

Cheers,

[TwoTired]

Pinhead ,TT or anyone
is the regulator there to regulate the voltage into the rotor or to reg. the V to the battery from the alt.

Other systems, such as those with permanent magnet alternators, can regulate via shunting or chopping excess alternator output.
Assuming you mean for the SOHC4.... 
The regulator is there to protect the battery from overcharge damage.  It does this by throttling the alternator's output capability (via rotor or field coil voltage) when it is capable of over charging the battery (battery full and engine revved up).  The bike's system voltage IS the battery voltage when all is working properly.  Keep the battery happy and the bike is happy.

Cheers,