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Discussion Starter · #1 ·
OK, so I have a '66 CB450(15k miles) at the shop that is giving me the fits as far as the charging system.
This is a genuine Bomber, without a voltage regulator in the system.
Battery voltage while idling: around 12.1V
Rev it up: maybe 12.3V
The ignition switch is on the 3rd position and light switch on HI.
Have replaced: rectifier with a Oregon Motorcycle Parts rectifier; stator with a later CB450K unit.
Have triple checked all wiring and connections, even in the headlight bucket.
Original stator had no output on the lighting coil, prompting stator replacement.
With replaced stator, appropriate AC voltage found on all leads from stator at stator plug.(+20V AC)
Seems to me it still doesn't charge as it should.
Hooked up amp meter in series on charging lead to battery from rectifier and saw a lessening of current draw, but still it didn't go positive; ie. it wasn't charging.
Am I missing something and/or misinterpreting something?

NE in PDX
 

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Sensei
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You should be getting more than 20VAC out of each "pair" of wires when reading at revs...More like 60VAC....It is possible that the magnetism of the rotor has diminished ... (impacted/dropped?).... The cure is likely a new rotor......
 

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Discussion Starter · #3 ·
This 60VAC should be measured between each leg of the stator and GROUND or between legs, say pink and BROWN(common)?
Thx for the help.
NE

Well heck, if I read your post thoroughly I would see you stated "pair of wires". This reading is at 5000 rpm?
 

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Sensei
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... Measure wire to wire, color to color...On a later stator, it will be pink to yellow, pink to white and yellow to white........ Disconnect from the main harness...Just read raw output from stator... anything lower than 40ishVAC @ 5000 RPM is indicative of a problem.........Voltage should rise as revs do....Might only be 20/[email protected] (never measured there)
 

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Discussion Starter · #5 ·
Okey dokey, thank you sir. Will see what happens tomorrow.
The rotor has probably never been removed, so never been jarred. Just 40 some years old. I'll dig up another rotor....

NE
 

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you might verify the headlight switch, it could be failing to connect the second and third stator coils when the lights are on. mine is jumpered to always use all output regardless of headlight condition. with an upgraded regulator rectifier I have little fear of burning anything up, it only seems to charge at 12.5-12.8 nothing to write home about, but after a 500 mile ride last week, it does seem to be holding its own.. I may do a little wiring to see if I can cut out some of the weak connectors and sorry wire.
 

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Never heard anything more from 'CurbTiger'...like to know the outcome.
 

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Hi guys!!

Following this thread in order to solve a charging problem in my UK 78 CB500T .

When testing my stator I get the following results:

PInk to Yellow 40VAC plus at 4k rpm
Pink to White 40VAC plus at 4k rpm
Yellow to white 5VAC at 5k rpm

Is this a sign of a bad stator?

Thanks in advance
 

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Sensei
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Those readings indicate a good alternator....Any problems must be further down the circuit path (rectifier, regulator, wiring, or battery)
 
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