Post by: Davelu88 on February 27, 2023, 06:47:47 PM
Post by: Sesman on February 27, 2023, 06:49:25 PM
Post by: Davelu88 on February 27, 2023, 06:54:20 PM
Post by: Sesman on February 27, 2023, 07:03:40 PM
Post by: Sesman on February 27, 2023, 07:08:59 PM
Post by: Davelu88 on February 27, 2023, 07:14:12 PM
Post by: McCabe-Thiele (Ted) on February 27, 2023, 09:00:07 PM
Post by: Davelu88 on February 27, 2023, 09:23:53 PM
Post by: deltarider on February 28, 2023, 08:42:29 AM
Personally I would start by charging the battery fully with a charger then see what the volt readings are after standing overnight Then I would see what the readings are with the engine running. Could be you have already done this. When I've ruled out the battery then as has been said I would check earth's etc & charging voltage. [...]This ^. After a night at rest the battery, not connected, should read 12,6 V or more. When less, battery is nearing its end.
Start engine with fully charged battery. Switch on the headlight. Rev the engine from idle to say 3500 rpm, whilst holding your left hand in front of the headlamp and check if the light's intensity increases. When it does, there is charging. These are basic tests. Toying with the multimeter comes later... maybe.
Post by: K2-K6 on February 28, 2023, 08:59:51 AM
Going from 11.45 to 11.49 when revved shows there's negligible power coming from alternator to battery, for whatever reason that may be.
That's the problem to investigate. Basic connection check first, wires from alternator, everything around regulator rectifier to ensure no simple disconnect is present is initially a good place to start.
Post by: Sesman on February 28, 2023, 09:53:43 AM
Most likely problem is a poor ground/earth for either the field coil, regulator or rectifier.
Post by: McCabe-Thiele (Ted) on February 28, 2023, 10:04:42 AM
In 1974 I was taking a prospective buyer for a test drive in a brand new red Opel Ascona in Burton on Trent, I was held up at a set of temporary traffic lights on Balaclava Road opposite the Shell Station. As I started to move off when the lights changed to green the engine started to loose power it stalled - I saw smoke coming from under the bonnet edges so switched off the ignition and we alighted from the vehicle.
Vehicle was towed back to base and the battery had failed due to a dead cell short. New battery fitted & everything was okay - customer decided to buy an Audi 100 from me instead!
Post by: K2-K6 on February 28, 2023, 10:41:09 AM
If you loose one cell it tends to be below eleven volts (missing two from 12.6 gives 10.6) is a good indicator. In the eleven range, they're usually OK but can be toward end of life or just reasonably discharged from not have alternator input.
Post by: deltarider on February 28, 2023, 12:39:37 PM
Post by: McCabe-Thiele (Ted) on February 28, 2023, 05:37:19 PM
I cut around the top of the battery to separate the top section from the casing - pulled out the top - a load of what looked like thin sheets of glass fibre started to fall out from between the battery plates. I pulled them out & binned them washed out the sediment in the bottom as well as dipping the top with the plates attached into some clean water. I Araldited the top back on and filled with battery acid & put it on trickle charge overnight.
Incredibly the bike started first touch of the button, when I sold it six months later to a mate - I told him to never let it go flat - about six months later he let it go flat so had to fork out for a new battery.
Post by: Davelu88 on February 28, 2023, 07:20:03 PM
Post by: Sesman on February 28, 2023, 07:22:28 PM
Post by: McCabe-Thiele (Ted) on February 28, 2023, 07:38:13 PM
Post by: Oddjob on February 28, 2023, 08:01:14 PM
Post by: Laverdaroo on February 28, 2023, 08:04:53 PM
Post by: mickwinf on February 28, 2023, 10:26:34 PM
Post by: K2-K6 on March 01, 2023, 10:38:23 AM
I've had very few alternator confirm as failed over many years, they often get blamed but when changed the problem persists and ultimately found to be something else.
More recently had a car one go "clunk, thunk, clonketty, bonk" then charge light came on. Pulled over to inspect and found the drive pulley missing, just the alternator nose shaft sticking out with belt still going round it !
Got home to find that pulley wedged up under the radiator top hose, think that was the bonk of final resting place ;D
Closer examination showed that the one way sprag bearing in the centre of it had seized then the vibration resulting from that had taken it apart.
It's an overun pulley so that at low diesel engine speeds that can decelarate in abrupt phase doesn't need to be shocked through the alternator (the spindle and rotor can overrun belt speed to avoid the phase change) that also makes them quieter. It was getting a bit noisier at tickover before this, but no direct idea where that was coming from.
Two mates have similar engine that we share knowledge on, both checked to find the same seized sprag, and so preventative swap was done.
You do need special tool though ::) as many of these things do nowadays.
Post by: Bristolbadger on March 04, 2023, 11:07:36 PM
Anyway, fully charged new batt and getting 19v at idle. 🫣 Using an M&P parts solid state reg/rec. Was blowing headlight bulbs, led's etc so out with the multimeter...
Yet to check all the connections especially a solid earth. But suspect the reg/rec at this stage as have heard similar issues from others on various threads... what else should I be focusing on at this stage?
Tapping into all your combined wisdom, what procedure of tests would you start with. Will get some pics up of the wiring but I must say I used the original bullet connectors from the alternator into the new reg/rec and trusted all was good after initial tests, from memory the yellows all tested very similar Ohms
Not great with elecs but have the basic skills and understanding, was wondering when I'd have a leccy problem to solve with this mongrel, she's taught me a ton already and still learning... constantly
Post by: Bristolbadger on March 04, 2023, 11:10:32 PM
Read this with interest but I've a problem with overcharging. If it ain't one thing...Oops should add I'm taking 750 but guess it's all vaguely similar?
Anyway, fully charged new batt and getting 19v at idle. 🫣 Using an M&P parts solid state reg/rec. Was blowing headlight bulbs, led's etc so out with the multimeter...
Yet to check all the connections especially a solid earth. But suspect the reg/rec at this stage as have heard similar issues from others on various threads... what else should I be focusing on at this stage?
Tapping into all your combined wisdom, what procedure of tests would you start with. Will get some pics up of the wiring but I must say I used the original bullet connectors from the alternator into the new reg/rec and trusted all was good after initial tests, from memory the yellows all tested very similar Ohms
Not great with elecs but have the basic skills and understanding, was wondering when I'd have a leccy problem to solve with this mongrel, she's taught me a ton already and still learning... constantly
Post by: Bryanj on March 05, 2023, 08:05:44 AM
1 duff regulator
2 volt sense wire at reg showing less than battery voltage
Post by: Sesman on March 05, 2023, 08:15:35 AM
So in short, as BryanJ has suggested…
Post by: Bristolbadger on March 05, 2023, 12:01:02 PM
Only 2 things cause overchargeOk that makes sense thanks Bryan. So if I'm to replace the unit which should I go for,
1 duff regulator
2 volt sense wire at reg showing less than battery voltage
DS https://www.davidsilverspares.co.uk/CB750K3-FOUR-1973-USA/part_220371/
Or Electrex
https://www.electrexworld.co.uk/acatalog/RR24_-_Regulator_Rectifier_CB750F1_CB750K1-K7_CB750KZ.html#SID=439
Post by: McCabe-Thiele (Ted) on March 05, 2023, 12:19:20 PM
Plus the Harness repair adapter if needed.
I like the original adjustable regulator on my 400.
Post by: Oddjob on March 05, 2023, 02:40:58 PM
Post by: SteveD CB500K0 on March 05, 2023, 02:56:03 PM
Surely there’s something better nowadays?
Sent from my iPhone using Tapatalk
Post by: Oddjob on March 05, 2023, 02:58:13 PM
Post by: Sesman on March 05, 2023, 03:57:26 PM
Speaking of reg/rec failures my old 800VFR had an appetite for them. I always carried a spare on foreign trips until I learned a Yamaha variant was more reliable.
Post by: Bryanj on March 05, 2023, 04:11:15 PM
Post by: Sesman on March 05, 2023, 04:41:16 PM
Post by: Laverdaroo on March 05, 2023, 05:07:19 PM
Post by: Sesman on March 05, 2023, 05:28:43 PM
Post by: Bryanj on March 05, 2023, 05:41:38 PM
The voltage spike is far more common due to old and poor connections/ looms.
Personally i will use the original type until i cant get one
Post by: deltarider on March 05, 2023, 06:56:55 PM
The problem with the "electronic" ones is that they dont like either voltage spikes or reverse polarity. Now the reverse part can only happen by fitting the wrong battery or simply getting it wrong BUT i have seen, more than once, both done.And right you are. It was a German engineer who posted his findings on the German forum after having monitored and compared the OEM arrangement to aftermarket full electronic devices. He discovered the big resistor more or less 'senses' the ambient temperature - not so much the battery's temperature as I understood it - so in hot weather the charging is reduced somewhat, whereas in the cold, right after a cold start the charging is at max, because the resistor is still cold. I don't know how big the effect is and if it was designed on purpose by Honda or just a bonus of having that big resistor in the open.
The voltage spike is far more common due to old and poor connections/ looms.
Personally i will use the original type until i cant get one
Post by: Sesman on March 05, 2023, 07:29:31 PM
Post by: McCabe-Thiele (Ted) on March 05, 2023, 07:34:54 PM
Post by: Laverdaroo on March 05, 2023, 07:37:24 PM
Has all this elastic trickery been part of your career? I had to google some of that! :o
Post by: Sesman on March 05, 2023, 07:40:56 PM
Post by: Sesman on March 05, 2023, 08:40:47 PM
I spent 4 years at Leeds Uni learning how little I knew.
Post by: Bristolbadger on March 08, 2023, 11:29:25 AM
I've taken the plunge and ordered an Electrex one, hopefully more robust than my old one.
Also one of my stator coil yellow wires was a bit corroded and blackened. Is this common and maybe indicative of shorter problem...?
I can't remember putting new bullets on when I wired up the bike a few years ago and probably should have, so I'd like to renew the connection wires from the stator & field with new wire and bullets.
Is 10amp auto wire ok for this?(https://uploads.tapatalk-cdn.com/20230308/7e0c8b1fc671f5400aec51021d8238a8.jpg)
Post by: Laverdaroo on March 08, 2023, 02:34:40 PM
Giz a bell when you're in, fed and watered and we can have a yap, need to run some bits passed you, when 20 questions, yer know. Re yer chopper.................yer 750 that is ::)
Post by: Bristolbadger on March 08, 2023, 07:43:41 PM
Nick Ive buckets of the right barrel connectors for that set up if you havent got any and before you reach foir the nasty blue ended lumpy things ;)Cheers mate, I'm sorted for good connectors, need some 10amp yellow wire and some heat shield tho
Giz a bell when you're in, fed and watered and we can have a yap, need to run some bits passed you, when 20 questions, yer know. Re yer chopper.................yer 750 that is ::)
Not sure how far back into the coils I can go to solder nice fresh wire and connectors up and out of the cover.. will see when I take the alt off I guess