Author Topic: Testing Alternator etc  (Read 2550 times)

Offline Mike_Berkshire

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Testing Alternator etc
« on: February 04, 2025, 01:04:09 PM »
Hi all, can anyone point me in the direction of a testing approach for CB550 charging circuit. I have tested for voltage across the battery when the bike is running at about 3,500 rpm and Im getting just a smidge over 12 volts which is presumably the standing voltage across the battery. I have replaced the rectifier but not regulator; everything else is as I got the bike. I have had a trawl through hints and tips and the only thing I can find is a link which now leads to a game download site as opposed to a testing regime. Cheers, Mike

Offline Sesman

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Re: Testing Alternator etc
« Reply #1 on: February 04, 2025, 02:49:01 PM »
Mike.

Have you tried the CB550 manual in alladins cave?

Offline Sesman

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Re: Testing Alternator etc
« Reply #2 on: February 04, 2025, 03:10:40 PM »
Page 93 to 97. Start with the rectifier input and output voltages, remembering that the input is AC and output is DC . For the ‘input’ check between each phase and phase to earth.

My money is on a failed rectifier🤞
« Last Edit: February 04, 2025, 03:12:43 PM by Sesman »

Offline Mike_Berkshire

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Re: Testing Alternator etc
« Reply #3 on: February 04, 2025, 03:12:59 PM »
Thanks - ill give that a go

Offline Sesman

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Re: Testing Alternator etc
« Reply #4 on: February 04, 2025, 03:16:34 PM »
Page 97 shows the ‘static, off the bike method’ of testing the rectifier.

Offline ozzybud

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Re: Testing Alternator etc
« Reply #5 on: February 04, 2025, 03:34:28 PM »
First check that the field coil is getting energized with the key on engine off. Take the left honda nameplate off.
With the key on the three screws should become magnetic. Check with any steel object. The fiels coil is fed by 3 yellow wires #6  in diagram.
1976 Z50 YELLOW
1970 CT70 BLUE
1971 CT70H ORANGE
1972 CT70H GREEN
1973 CL200 BLUE
1973 CB350F RED
1975 CB360T RED
1975 CB400F BLUE
1975 CB550 ORANGE
1976 CB750F RED

Offline Bryanj

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Re: Testing Alternator etc
« Reply #6 on: February 04, 2025, 05:28:30 PM »
There is also a bulletin on the 3 phase charging circuit operation in either Ashs dropbox or Alladins cave.
I would say 95% of charging problems are bad connections

Offline BigAl (Alan)

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Re: Testing Alternator etc
« Reply #7 on: February 04, 2025, 07:14:21 PM »
Completely agree Bryan, normally poor dirty connections will cause voltage problems.
Another factor that is now starting to happen on these old bikes (50+ years) is the copper winding insulation (stator & field coils) are starting to degrade and fail.  Most Kawasaki stators that I have refurbished in the past have failed a high voltage test to the frame, not because of electrical use, the insulation material is becoming less soft and flexible.
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

Offline deltarider

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Re: Testing Alternator etc
« Reply #8 on: February 04, 2025, 07:23:38 PM »
[...]
I would say 95% of charging problems are bad connections
So... also check for chafed wires.

Offline Mike_Berkshire

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Re: Testing Alternator etc
« Reply #9 on: February 04, 2025, 08:44:05 PM »
Thanks for all the pointers. I will do some investigating at the weekend.

Offline Bryanj

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Re: Testing Alternator etc
« Reply #10 on: February 05, 2025, 12:16:30 AM »
All you need is a decent multimeter that gives accurate low resistance readings

Offline BigAl (Alan)

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Re: Testing Alternator etc
« Reply #11 on: February 05, 2025, 03:42:04 PM »
A good quality multi-meter is ideal, image attached. Most stator windings that I measure (end to end are around 0.5 ohms) but the test voltage test is only around 6volts.
Back in the day, did you have an high volt coil winding insulation tester (test point end of a winding to the stator frame) ? If you did, what was the  test voltage on the machine ?
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

Offline ST1100

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Re: Testing Alternator etc
« Reply #12 on: February 05, 2025, 03:52:04 PM »
Back in the day, did you have an high volt coil winding insulation tester (test point end of a winding to the stator frame) ? If you did, what was the  test voltage on the machine ?
What was the operating voltage of that device?
The "Mega-ohmmeters" regular avail are operating with 250-500-1000V... might be a bit harsh on coils designed for like 60V... but the poof of smoke eases spotting the leak...  ;)
STOC #637
'00 ST1100Y, '04 ST1100R, '07 NT700VA, CB500K2, CB500K1...

Offline Bryanj

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Re: Testing Alternator etc
« Reply #13 on: February 05, 2025, 04:23:43 PM »
I just used the Honda Sanwa SP10D (analogue meter) for resistance and a megger for insulation, wiring disconnected of course

Offline BigAl (Alan)

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Re: Testing Alternator etc
« Reply #14 on: February 05, 2025, 04:30:20 PM »
Currently using my insulation tester 250v/500v/1000 (as image) which I think (250v) is a bit high...I'm guessing that the workshop machines where rated at 100v/125v?
When the stators come back from the rewinders they measure perfectly (scale 250v) value 200M/ohm's
Memories...When I was a lad at Tech, I was told...It's not a 'mega' it's an insulation tested...as a 'hoover' is a vacuum cleaner
Current bikes:-
Honda CB750 K4 (1974) USA
Honda XL500S (1980) UK
Honda CD175 sloper (1968) UK
Honda CB1100A (2013) UK
www.alans-electrics.co.uk

 

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