CB200 Charging issue


Everything checks out. If that new R/R doesn't do the trick, it might be time for a new stator and/or rotor.


New Member

This is what I figured out and if you don't mind, let me know if this makes sense. Your regulator won't allow me to start the bike until I ground the green wire. I run a jumper from the plug to ground and I get full voltage to my headlight and I can start the bike. With a radioshack rectifier I get the same behavior, where I need to ground the green terminal to start the bike. This happens even though I ground the bodies of the rectifiers. With the stock rectifier If I don't ground the body, I get the same behavior as the replacement rectifiers without grounding the green wire. I feel like maybe that circuit in the green wire is running through something incorrectly and is not grounded like it should be. Does your R/R normally work a direct plug-in on a bike with stock wiring. My wiring is mostly stock with some rewiring done by the PO. BTW- all three rectifiers give me the same voltages once I get the bike started.

Thanks for any additional insight you can provide.


The Sparck Moto unit does not use the case for grounding, it's only for dissipation of heat. The green wire must absolutely be grounded.


New Member
The green wire circuit was only being grounded through the original rectifier. I ran a jumper from an open bullet connector on the original harness underneath the seat to a chassis ground and then the sparck moto R/R worked as a direct plug-in. The PO had taken the bike apart and put it back together and replaced some wiring so its not 100% stock wiring. I used the mounting bracket from the original and put it back in the stock location. I then just unplugged the voltage regulator but left it mounted. I don't think this will solve my charging issue because I tested by grounding the green circuit earlier, but I'm putting everything back together and will ride it as is until I get the original stator rewound for higher output. The new R/R can only help and will be ready for hotter stator in the future.

thanks Sonreir,



I know this is an old thread but I would like to revive it as I seem to have EXACTLY the same problem as the original poster on a 1975 CB200T. To the OP: did you ever manage to solve your problem ?

Battery test
Measured across the battery, I'm getting about 12 v DC at idle, but only it goes up to 12.6 v DC at high revs, not enough to charge the battery. It drains slowly though, and I can use the bike every day for a week or two before I have to recharge the battery.

Stator test
I measured resistance between the three leads coming out of the stator and get 0.6, 1.8 and 2.1 ohms, which is exactly what the OP got on two different stators. I've seen many videos on youtube saying that anything above 1 ohm is a sign of a bad stator, but here we have 3 stators producing the same readings. Are they all bad?

There is no continuity between the stator leads and ground.

AC voltage readings between the three leads (A-B, B-C, C-A)with the stator plug disconnected (all three leads are black):

idle / 3000rpm / 5000 rpm
16 / 40 / 65
10 / 25 / 42
6 / 16 / 22
Is this enough AC voltage to charge the battery?

Rectifier test
(Pink and yellow wires come from the stator. Red/white goes to the battery. Green is ground.)
From yellow to red/white (+) = 0.6 ohms
From pink to red/white (+) = 0.6 ohms
From green (-) to red/white (+) = 1.3 ohms
No reading in the opposite direction.

There is a separate voltage regulator with three wires: yellow, green, black.

Hopefully someone can pinpoint why the battery isn't charging.


Well-Known Member
IIRC there are two "sides" to teh stator. One charges through the regulator/rectifier all the time and the other only connects when the headlight is on. Many people splice the two sides together to get full charge all the time.

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