Regulator Rectifier - can a later Yam model be used?

BarrieC

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Guys,
thought I would come to the guru's for a definitive answer on this one!
My combined Reg/Rec is testing faulty on the diodes, so I thought I would ask on our UK facebook Forum if anyone new of a replacement that would work, that did not cost near a £100
Been advised that later model Yamaha's XJ650 and even units with fewer connections (5 not 7) would work - yes the colour combination is the same, but I cant see how a bike with a standard Permanent Magnet Alternator would have the same set up as an XS650.
Main concern being that the Green wire out of the XS Unit is providing the "ground" to switch off and on the magnet via the brushes and therefore regulate the charging
Lots of "other" Yam units available, so yes it would be great if other units do work, but i really have my doubts
Thanks
Barrie
 
You are correct in that the regulator part of the combined units works differently in spite of similar wiring colors and only regulators designed for electromagnet alternators, not PMAs will work. There are many threads here about changing to separate units sourced from other venders to create an inexpensive and reliable rect/reg. The rectifier part is easy, just about any 3 pole rectifier rated 30 amps or above will reliably do the job. Getting a correct regulator takes a bit more effort.
This thread found in tech, written by two stalwarts here, is probably the gold standard in wiring and parts selection; https://www.xs650.com/threads/diy-reg-rec-5twins-and-jim.55842/
Buying cheap aftermarket combined rect/regs is a crap shoot at best. Tales of the short life of low quality units are very common.
Mosfet based combined rect/regs from quality venders do exist and are not horribly expensive.
 
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You are correct in that the regulator part of the combined units works differently in spite of similar wiring colors and only regulators designed for electromagnet alternators, not PMAs will work. There are many threads here about changing to separate units sourced from other venders to create an inexpensive and reliable rect/reg. The rectifier part is easy, just about any 3 pole rectifier rated 30 amps or above will reliably do the job.
This thread found in tech, written by two stalwarts here, is probably the gold standard in wiriing and parts selection; https://www.xs650.com/threads/diy-reg-rec-5twins-and-jim.55842/
Thanks Gary, while i'm stuck in the house at the moment, I tested out the unit and started delving deep into the subject, so I can have everything ready.
Just had a look at XJ650 and XJ750seca wiring diagrams (probably had a different name in the USA)
Was surprised to find a non PMA charging set-up with an identical wiring set-up to XS so they would work as an alternative. But, I will review the link
Cheers for the advice Gary, keep up the great work!
 
I think you are on the right track yes any rect/reg sourced from a brush style alternator bike will work. Like the 80 up XS650 almost all later regulators work by interrupting the ground brush circuit. As long as you check the wiring diagrams for that type you should be good. Appending your "compatible" findings to the thread I referenced above would be a very good thing!
The "gotcha" is old combined rect regs are getting unreliable from age of components. I think the jury is out even on NOS type replacements.
My personal findings have been the original mechanical regulators from the 79 down systems are more reliable than the old potted solid state units.
a guy selling Shindengen Mosfet and Series R/Rs for PMAs suggests and uses the two part unit for our excited field alternators.
He references a smart guy, I suspect it's one the two authors of the thread above.
https://www.roadstercycle.com/Five_wire_stator_setup.htm
 
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I had a good read of the thread, and only part I was unsure of is with the replacement 2 wire Regulator (Ground through body type) how can you tell it has the correct "when the voltage gets high, cuts off the Ground to the Rotor" characteristics?
I can only think, you need to find the vehicle with correct wiring set up, then look for the part - I'm sure the links and part number suggestions work over there. But looks like I will have to work that one out over in the UK (we just have useless access to parts, spares new or second hand over here (you would think we lived on a 3rd world island :rolleyes: oh, we do! )
I suppose, eventually we will all have to stump up for PMA's or start rewinding our own alternators and rotors!
 
That fiat part should be available in the "old country". A digital voltmeter up on the handlebars where you can see it while riding is your friend!
 
Hi Barrie C.
I’m new to the forum but have an electrical issue on my XS1B. It was the original reg/ rec.
My engineering mate fired this 4 pole bridge rectifier, he has the same one on his triumph bonnie. Pic attached.
Now it does work even on 4 pole but only shows 11.8v when engine runs.
 

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We’ve now order this. 5 pole will post on here when it arrives.
 

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Hi Barrie C.
I’m new to the forum but have an electrical issue on my XS1B. It was the original reg/ rec.
My engineering mate fired this 4 pole bridge rectifier, he has the same one on his triumph bonnie. Pic attached.
Now it does work even on 4 pole but only shows 11.8v when engine runs.
Define works?
Nearly all these rectifiers are 3 phase they will have 3 AC in, a DC out, and maybe a ground connector.
Problems with voltage now that you've replaced your rectifier are likely to be found in the brushes, rotor, regulator, or wiring harness in roughly descending order of likelyhood but testing each component's electrical values/ function is the only reasonable way forward.
 
Hi,
you might not get a response, adding onto my original thread, as its not the same issue or question. (XS1B is the earlier type B Alternator)
Best bet is to follow Gary's link above to read up on the options. Then probably start a new thread with any issues or questions
Hope that helps
Barrie
 
Sorry folks. Not wanting to hijack just add what issues I found with my bike. Or should I say my mate found. I’m no electrician. Just thought it may help.
 
No problem, just trying to help ;) Garys right, you have to look at all the components in the order he suggested, otherwise you will end up in circles.
Try this link to the TECH section under the main menu, always a good place to start:
https://www.xs650.com/threads/expanded-charging-system-guide-in-progress.10561/
Probably worth reading this one first to get an overall understanding
https://www.xs650.com/threads/9625

I can confirm that being an Electrician, does not help even with my qualifications and experience, but I am thinking of wiring my bike in Twin and Earth Cable :D
Cheers
Barrie
 
Not electrician and no experience on working with PMA Systems
But many years with problems on XS 650

XS 650 has regulator that adjusts the physics to the alternator rotor to keep the output at desired level

THE PMA systems have magnets that produces physics with rev .and cooks off the surplus in various ways
( as I understand it maybe wrong )
please check that link

https://www.shindengen.com/products/electro/motorcycle/reg/

They can be better or worse in design but in essence as I understand it totally different working methods
and are pirated ( Check Youtube )

The XS 650 regulators and rectifiers have cheap tested solutions here on the forum so it is really not wort the risk trying another
Should it output to high current other parts may suffer
 
Hi,
the link you sent is not really relevant as all the diagrams relate to Permanent Magnet Alternators, so there are no brushes as in "our" Electro Mechanical Alternators (think that's best way to describe them)
I have done the research on the forum via Gary's link and there is a suitable Regulator available (but not so cheap in the UK!) same with the Rectifiers of correct amp rating.
Its gonna take a while to find the right parts over here, in the meantime, if I can get a compatible Yamaha one that is for an Electro Mechanical Alternator - confirmed by the wiring diagram, I will have to go for it
But as Gary says, these are still old items
Thanks
 
Ahh sorry if I got it wrong there

Been advised that later model Yamaha's XJ650 and even units with fewer connections (5 not 7) would work - yes the colour combination is the same, but I cant see how a bike with a standard Permanent Magnet Alternator would have the same set up as an XS650.
 
Ah, confusion all around, no probs. Unfortunately at the minute i'm stuck in the house NOT the garage, so have been going deep into this subject and ended up being a bit of a nerd (do you have nerds in Sweden?)
Thanks for your input Jan, reckon I've got the info. I need now (just not the parts LOL)
:D
 
No problem, just trying to help ;) Garys right, you have to look at all the components in the order he suggested, otherwise you will end up in circles.
Try this link to the TECH section under the main menu, always a good place to start:
https://www.xs650.com/threads/expanded-charging-system-guide-in-progress.10561/
Probably worth reading this one first to get an overall understanding
https://www.xs650.com/threads/9625

I can confirm that being an Electrician, does not help even with my qualifications and experience, but I am thinking of wiring my bike in Twin and Earth Cable :D
Cheers
Barrie
Cheers Barrie for the links will have a read up. 👍
 
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