Regulator and Kickstart alternatives

Ivan Mihajlovski

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Hi, I have XS400 Special 1980. I bought a new battery and after 2-3 days of riding, battery dies, the starter doesn't have enough power to spin and after some time it completely stops. I think it is because of the regulator. It is the original one as far as i know. However, shipping from ebay to my country is a little bit expensive. Do you know any other alternative regulator that can work for me. Also i am missing kickstarter pedal. Same as for the regulator shipping it's expensive. Any bike that has the same or similar dimensions and teeth.
 
There are a lot more tests to do before blaming the regulator. Not sure what models you would have gotten in your country. If it's an electronic regulator they were pretty reliable.
If it's the old mechanical type definitely replace it. There are some aftermarket ones available.

The most common charging issue is wire damage where the stator/field coil wires enter the casing under the bottom left of the crankcase. There are resistance tests to be done which are detailed in the Haynes manual in the thread at the top of The Garage.
 
I have these two. Can you tell me how they are called and what are their purpose. I am currently charging my battery to full charge, then i will perform tests and write the results. On a lower charge i got 13V at 3000RPM. I don't know if that's fine or not.
 

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The one with the fins in your pic is not the stock one. It may even be a combo unit.
 
I know if the finned one IS a rectifier or combo rec/reg it needs at least 3 wires of the same color going into it. Disregarding any other wires of course.
 
Looks like the finned one is probably just a rectifier.
Would most likely have more wires to regulate the field coil.

I would still highly recommend you check the resistance of the stator and field coil wires before bothering with the regulator.
Test all for resistance to ground too.
The rectifier diodes are also an easy test with a half decent multimeter.

Eliminate those and you know it's your regulator.

As mentioned the tests are all detailed in the Haynes manual.
 
I tried the regulator checked as said in the manual. With disconnecting it from the connector, i couldn't get any reading when i place 1 pole on black lead wire, and the other pole on the casing of it. I had an wire explosion a few months back, thats when the problem started. I think it's just burned regulator. Here are some pictures of the regulator and rectifier. Can you suggest any motorcycle or car that has same regulator which i can use. There are some original that are on ebay but shipping is expensive for my country. Please let me know.
 

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You need to rip all that out and start all over, but I'm pretty sure you are not competent enough to do it. It looks like you are running e regulator on top of a regulator/rectifier and trying to make that work, It won't............EVER. You have too many wires there.
 
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I don't know, the previous owner drove it like this and had no problems. He went on 2000km ride. I really dont know any harness wiring, thats why i ask for easy alternative with new part.
 
By looking into the manual, this regulator replaces the original one.
 

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https://www.babbittsonline.com/oemparts/l/yam/50041ea6f8700209bc7868fb/1980-xs400g-parts This site has all the OEM part numbers. Use this to search for correct parts. When you use these numbers some seller will also list other models that use them. You can then expand your model searches.

https://www.ebay.com/itm/1978-XS400...764390?hash=item2caf30af26:g:MagAAOSweWVXf-FV Stock rectifier.

https://www.ebay.com/itm/Yamaha-XS4...994524&hash=item5208735a4d:g:I9oAAOSwcuRa0Ltf Stock regulator.

Prices are all over the place for new and used. A local salvage yard may have ones also. Rectifiers can be tested off the bike by using a multimeter. The manual has the test in it. Regulators need to be on the bike while running to test. In your pics you have wires attached to the housings. This is wrong and might be part of the issue or what caused the melt down. All I can say is follow the wiring diagrams in the manual to see where things go.
 
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I found an topic on the forum. There was an post that said that regulator and rectifier should have good grounding, that's why the housing of regulator and rectifier are connected both to the frame of the motorcycle. Also, i performed the tests while they were disconnected as stated in the manual.
 

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You can check the regulators with every recommended service manual method on earth and sometimes they will pass and still be bad. Why the last definitive test is always a KNOWN GOOD regulator. The manual tests help but are never the 100% proof of good/bad as there are simply too many different ways a reg can fail. Why some manuals do not give a way to test them at all, only get another new one.
 
Part of your issue may well be the finned unit, in pic you have 3 yellow, 1 red. 1white. and 1 black wire there. Or, too many wires. You need the 3 yellow and the red and black for output and ground but the white? No rectifier has a wire there. Unless it is a combo reg/rec. Rectifiers only have 5 wires total.
 
Well as you can see in the pictures I sent, white is not connected to anything on the motorcycle. That's how I got it from the guy that had no problems. I rebuilt the starter and had an shortage while starting the bike. Something smoked out. That's why I think that's the problem.
 
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