Author Topic: 1971 200cc Yamaha CS3B - 1971 - Regulator issues  (Read 193 times)

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Offline vanhelZ1ng

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1971 200cc Yamaha CS3B - 1971 - Regulator issues
« on: March 05, 2019, 07:33:13 PM »
Can anyone advise me please ?
On the bottom of the regulator on my leccy start 1971 Yamaha CS3B are two metal tags.
One i understand takes the thick light green lead coming from the Generator
What goes on the other tag please ? is it the fused positive lead from the battery ?
Coming out the other side of the regulator is a connector block that links in nicely with a connector coming out of the main harness.
Also there is a single red wire coming out to ? does that link up with the red wire in the main harness that goes to the ignition switch.

Finally would it be simpler and more efficient if that old regulator got ditched in favour of a more modern solid state one

Offline Astute Greaser

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #1 on: March 12, 2019, 05:58:31 PM »
Hi VanheklZ1ng
Go to the manual section and download CS3B
https://www.aircooledrdclub.com/manuals/CS3B.pdf
Section 6 shows connection diagram, but could not see wiring diagram.
I have got this in my Haynes and will load up for you when I get scanner to behave.
As your bike is predecessor of my RD200A find pics but check same as I can't say
Green top tab
Red battery bottom tab
Red wire (next to white cable tie) out of back regulator goes back into the loom via dual connector.
« Last Edit: March 12, 2019, 06:07:49 PM by Astute Greaser »

Offline Astute Greaser

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #2 on: March 12, 2019, 06:35:32 PM »
Find download but is for UK CS3E also 71 vintage? Can anyone comment about models differences?
Can't comment on solidstate but the electric start may complicate matters

Offline vanhelZ1ng

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #3 on: March 12, 2019, 10:19:13 PM »
Thanks for your help. much appreciated.
Thanks for your information, help and advice.
As is sometimes the case, you find things out by trial and error.

The Haynes manual says that the RD200 has negative earth but the CS3 has positive earth....ok good start.

Nothing else confirmed this, but who ever had connected a battery previously might have connected it with a negative earth (as you
 might assume) that might have polarised the voltage regulator.
The starter relay only clicked when I hit the starter button ?
After I accidentally caused a big short in the regulator (trying to take the lid off when it was still live) when I came to try the starter button 5 mins later,  it connected and started spinning the engine...Had I re-polarised it ?
Either way with a new battery it spins over lovely with a cracking spark...just got to try it now with some petrol
Yes, maybe because of the electric start a std solid state rectifier might not be suitable
Your RD looks great by the way............

Offline Astute Greaser

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #4 on: March 12, 2019, 11:36:09 PM »
Very confusing on which is earth. ???
My old Haynes published 74 says YCS3E, YCS5E and RD200 positive earth under chapter 6 Electrical system battery type, which is definitely wrong for RD200 as wiring diagram clearly shows negative and as I'm the original owner I know its -ive earth.
If you go to the CS3B manual download, pages 67 & 69 it shows battery -ive to earth.
Typical conflicting info!!! Anyone else out there got CS3B please!!
However if yours working well on +ive earth, don't fix whats not broken.
As the starter is DC if polarity wrong would the engine go in reverse? Put the bike on center stand in high gear and try to electric start and see what direction the rear wheel goes? Think I'm spouting load of rubbish!
My engine out at moment (well has been last 43 years - I'm on it) but yes the starter relay in the regulator box only clicks when start button pressed. Suspect when you shorted out, you blew crap off of contacts that then allowed the starter to work, but you'll never know.
My flasher unit didn't work when I reassembled harness. Stripping the can it was like 3 teaspoons of sand poured out, just aluminum corrosion. Cleaned the contacts and all good again.
Like the early style of your bike, looks all together, I'm presuming USA import. Surprising its the bones of the RD. Shows how technically advanced the Japs were.
So when are you going to steal yourself to fire up that engine?
PS
See Foy has simultaneously given similar info on Haynes. Its like waiting for a bus.
« Last Edit: March 13, 2019, 12:20:38 AM by Astute Greaser »

Offline vanhelZ1ng

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #5 on: March 13, 2019, 09:01:23 AM »
Hi
Thanks
My Haynes manual is dated 1977 and in the past they have been known to be wrong, so i approached the info on battery connection with some caution even though on the opening page of Section 6 : Electrical system, it does say negative earth for the RD200 and positive earth for the CS3 models.
Anyway I have gone through all the wiring very carefully and everything is working at the moment with a positive earth.

Good point about which way is the engine spinning ?.....must check that out.
I had taken the plugs out and it was buzzing away to itself with the starter motor.
I had issues with corrosion in the LH switchgear and the horn button, took me an hour or so to sort it all out.
The bike carried a Minnesota plate when I got it (ex D & K) and on the headstock plate it says 4/71
Its on Std bore and other than the tank bashed in.......its not bad....it was the colour that sold it to me...
It needed a chainguard and a kickstart for starters
Yambits as usual came in handy for the smaller stuff and everything is now primed and ready to go.
Just leaves the question of when do i put the petrol in and hit the button for real !!
Take care.

 

Offline Foy(notFox)

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #6 on: March 14, 2019, 11:07:36 PM »
Can anyone advise me please ? (Attachment Link)
On the bottom of the regulator on my leccy start 1971 Yamaha CS3B are two metal tags.
One i understand takes the thick light green lead coming from the Generator
What goes on the other tag please ? is it the fused positive lead from the battery ?
Also there is a single red wire coming out to ? does that link up with the red wire in the main harness that goes to the ignition switch.

Yes. The tag marked M (for motor) takes the thick light-green wire (from the starter generator) that is bound into the loom. the other tag (marked B?) takes the thick red lead from battery-cable and, if the bike has its original red battery-cable (so many bikes have been butchered here), it should have another, thinner, red wire coming from it which then connects to the fuse. the other end of the fuse assy wire connects into a single red wire in the loom a few inches from where the thick green one comes out and the red wire from the regulator connect into the loom at same place as the thick green wire
 


OEM YCS1 to CS3 +VE cable. connects to B tag on regulator and to fuse
« Last Edit: March 14, 2019, 11:59:29 PM by Foy(notFox) »
CS3B, AS3, RD125, RD250C, Honda SS50ZK1.

Offline vanhelZ1ng

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #7 on: March 15, 2019, 09:14:18 AM »
Yes,
you are absolutely correct with all that information, thanks for confirming it.
I ended up doing mine slightly different, but hopefully ended up with the same configuration.

I ran a red lead from the battery  to the regulator.
Then I  ran a another fused red lead from the battery which then split into 2 leads via a connector.
One lead picked up the thin red wire coming out of the regulator and the other lead connected into a thin red lead that was in the main harness and runs up to the ignition switch.
All seems to be working ok but wont be attempting to fire the bike up for a couple of weeks

Offline Foy(notFox)

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Re: 1971 200cc Yamaha CS3B - 1971 - Regulator issues
« Reply #8 on: March 15, 2019, 11:03:16 AM »
In a roundabout way this takes us back to the -VE/+VE earth thing....

If the bike was +VE earth the red lead would just be a single wire and the black one would be like the one in picture above. Unless the convention is that the colour also changes with the polarity. Like earth is always black even if it's coming from the +VE terminal  :-\   
CS3B, AS3, RD125, RD250C, Honda SS50ZK1.