Topic: Control the charging and see when wrong

[PeWe]

I have installed a very good gadget on my K2 that has had charging issues, probably from the beginning of the build.

I installed a voltagemeter between the speedo and tacho.connected it to green and black wires inside the headlight bucket. I had to crimp 2 Y-wires since all were taken

https://www.ebay.com/itm/LED-Digital-Motorcycle-Car-Voltmeter-Indicator-Voltage-Volt-Gauge-Panel-Meter12V/223531707201?ssPageName=STRK%3AMEBIDX%3AIT&var=522283515352&_trksid=p2057872.m2749.l2649

I could see that voltage suddenly changed from healthy 14V to 12 something.
Did not help to clean connectors and make sure tight fits plus adjusting the regulator.
I replaced the regilator today, got a good old one never opened. Now stable function after core gap adjustment and adjusting max voltage screw
The voltage meter show how it works and the correct 14V after a while without passing 14.5 V.

[bryanj]

Because the regulator is mechanical the moving contact can stick causing problems

[PeWe]

Mine had problem like sudden shortage or open wire somewhere. It could work fine for 10 minutes then problems in constant speed. Huge leap from 14V to low 12V.

[bryanj]

Thats a typical sticking contact blade, in the technical documents there is a Honda bulletin explaining how the 3 phase charging system and regulator work, if you read that you will understand

[pjlogue]

PeWe, You might consider running your wires directly to the battery.  This would eliminate any voltage drop from other drains on the circuit you currently have it on.  This would give you direct battery voltage reading.  Any black wire inside the headlight bucket goes through the switch and bullet connectors.

-P.

[Jerry Rxman Griffin aka MuthaF'er]

Or to the input of the key switch

[Don R]

 I put one on my gl1000 windjammer that has charging ports for my phone in addition to the voltmeter.

[PeWe]

This voltmeter can't be connected direct to battery, it will lit constantly and need a fuse close to battery too if wire will get its insulation squeezed off.
If connecting it to coil feed, I guess the voltage drop will be as it is now at black, green in headlight bucket.

The interesting thing here is the voltage changes and have some drop in mind compared to battery direct.

I  can see when regulator kick in the mode at around 4000 rpm and how much coils, lights, blinkers will take when on. All can be switched off and voltmeter still measure as long as ign switch is on. It's also visible why the battery always should be fully charged when adjusting.
I see that 14V need some time after lower speed, blinkers taking 42W, brake lamp 21W upon headlight and coils. It climb steady to over 14V. Even if we have law bout headlight on daytime, it must work when off without overcharging.

I checked the charging chapter in CB750 shop manual. Adjusted gaps, cleaned point surfaces. The continuity of all leads measured when assembled. Problem here intermittent indicating regulator not wanna stay at high mode.
Attached that chapter...
I have not found a service Bulletin about sticking regulator. I had that problem in mind when trying to get it to work.
Maybe the old Service Bulletin no1? http://hondachopper.com/engine/bulletins/bulletins.html
That list does not help without the bulletins.

Easier to find a better regulator as quick fault trace. Next should be to replace the coils when they could have intermittent shortage. Seems to work fine now.

I might send the old one to Germany for upgrade. There are guys on the German CB750 forum that upgrade the regulator to electronic, better voltage levels at lower rpms. Might be something if riding a lot on lower than 4000 rpm.
http://www.cbfourclub.com/boerse/756.htm
Electronic charge controller for CB 750 Four
No more cooking
Full charge current already at 2000 rpm
Maximum charging voltage 13.9 V for gel batteries and pure lead batteries urgently needed !!
Original optics cast in the old original housing, therefore absolutely moisture-proof !!
Prices: For club members 55 €, for non-club members 75 € (in exchange for old controller) each plus shipping.

I like the old school charging system. It is a part of the bike as well as the point ignition.

[PeWe]

One more thing... This thread is not about fault tracing the charging system. I'm sure Twotired has covered that
It's about the handy voltmeter easy to install and see whats going on while riding the bike.

But, I appreciate the ideas about whats wrong too of course

[seanbarney41]

My thing?...ignorance is bliss, right?  Leave the damn charging system alone.  Just ride your damn bike once in a while with a battery.  No big deal.  Never had a chargeing problem with cb750.

[PeWe]

I did this due to charging problems and drained battery.

Everything to do with the bikes is up to the owner, ride dead stock or modify it. Look, functionality and engine.

[bryanj]

There is no bulletin about sticking regulator, it is a description of how the charging system works and a bit more detailed than the link you posted.
What happens is that the moving contact sticks on the pivot and stops between the two contact points giving no charge at all, usually driving over a road bump frees it and it carries on OK till next time it feels like sticking. I had this on two different 500's and you could only tell it happened at night when the headlamp went dim, never bothered to change them out as they still worked perfectly 90% of the time and, being younger then, I rode flat out every where so hit lots of bumps to restart the charging.
Connecting direct to battery is a bad idea as the meter would be on all the time with a consequent current draw that will discharge the battery

[PeWe]

Bryanj, you are right that must be what my old regulator did 1/3 of the time or more. I noticed back in business on road bumps

 Weak mode often enough to get weak battery and almost not start on starter after a 100 km ride in 80-90 kmh.
-How to fix that?
I had tried to adjust core gap to 0.8mm
Checked the point gap 0.3-0.4mm.

My new (old) regulator work fine. But I can now see why battery must be fully charged when verifying voltage adjustment.

It take some time to come back to 14-14.2V after braking, blinkers, riding under 3500 rpm. Than back to 4000-6000 cruising for a while and see the voltage creeping up. This despite LED H4 with parking light. STD H4 cause higher voltage drop. Switch off headlight to ensure 13+ V in slow speed / low rpm.

Yes, I rode my bike different when younger. Faster in the city as well as the roads around town.