DIY Reg/Rec. 5twins and Jim

Jim

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This section deals with the '80 and newer A type regulator system. For '79 and earlier bikes, see comment #2.
Comment #3 discusses using modern rectifiers.



So, I've been getting quiet a few PM's lately about how I wired my reg/rec on the 80SG resto. I know there's a lot of info on this site already about this...but most of it's in comments and not in it's own thread... at least I haven't found one. So here's a thread to put all the info in one place.
First up, the type 'A' regulator. Here's the schematic to wire it up as a direct replacement for the 80 and up XS650 using the Windy Nation 30 or 35A rectifier and the Fiat VR-794 regulator

Reg-Rec cropped.jpg

The VR-794 Fiat regulator can be sourced here. On any given day it's about 15 bucks.
Looks like that one is no longer available. Rock auto has a VR-170 that looks like a good replacement.... here.
The Windy Nation rectifier can be sourced here. On any given day it's about 10 bucks.
Depending on shipping and your scrounging abilities, this can be built for under 30 bucks.

Using your old reg/rec as a pattern, cut a piece of flat sheet the same size and drill the mounting holes. I suppose any metal would work, but aluminum has good heat dissipation qualities. Apologies for not having exact dimensions here, but I just did a one-off for my bike... I hadn't planned on doing a write-up of it. Here's a shot on mine next to the original for comparison.

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The notch on my plate is for something else on the bike and isn't really necessary.

It's highly recommended you use some heat sink compound on both components for better heat dissipation.

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OK... in this next pic, the red and black wire are reversed from what they should be. It was late at night when I built this one and I made one of those mistakes one makes when one should be in bed instead of holding a soldering iron..... I crossed the two. :er: When I connected it to the bike I heard the little "tink" as the fuse blew and immediately knew what I'd done. :doh:

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So.... for the Windy Nation 30-35A rec. the red goes on the left and the black on the right.
Another change I made was the wiring. With it clamped coming out the lower left as shown, the harness came a little closer to the chain than I was comfortable with. I rerouted it so it comes out the top left. Sorry, but I didn't get any pics of it rewired and rerouted.
EDIT: Here's the connector you need if you're not using your old one. It's about 3 and a half bucks from Vintage Connections. You can't beat that. These are excellent quality parts.

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That's about it. Hope this helps somebody.
 
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This section deals with the earlier B type regulator. It's written by 5twins. So, take it away 5twins....



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OK, here I'll talk about the 'B' type regulator needed for the '70-'79 charging systems. There was a change in the 650 charging system in 1980 and it had to do with how the brushes were wired. On the '70-'79 systems, the inner brush is grounded full time to the stator housing through it's mounting screws and the outer brush is fed regulated power from the regulator. The 1980-on systems are sort of the opposite. Their inner brush is fed constant power from the harness (switched on and off with the key) and the outer brush is fed a regulated ground from the regulator. So, that means 2 different types of regulators are needed. As Jim discussed above, the '80 and newer systems require a ground switching type 'A' regulator. The '70-'79 systems require a regulator that switches or regulates power to the outer brush and that is called a type 'B' regulator. The most common one we use is the VR115 from Standard Motor Products. Many other manufacturers make this under a different part number and I'll list some later.

Now, this is a regulator only, not a combined reg/rec like the '80 and newer models used. The '70-'79 models used a separate rectifier. The same Windy Nation rectifier Jim used above can be used as a replacement. You can mount the VR115 in the same spot as the original regulator on the '74 and newer models. I'm not sure about the '73 and older models but it can probably be done as well .....


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Only one mount will align with an original so a small triangle-shaped adapter or extension plate will need to be made up to reach the other .....


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There was a small issue with the lower right mounting bolt in the pics above. It stuck out too far and hit the side cover so I simply flipped it around. The bolt head was still a bit close so I put a button head Allen in .....


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Wiring it up is pretty simple. The black and green wires from the VR115 will match up to the same colored wires in the 650 harness. The red or orange and yellow wires on the VR115 get combined and connected to the brown wire in the 650 harness. The VR115 harness is very short, way too short to reach up on top of the battery box where the regulator harness plug is. Instead of cutting the VR115 plug off and soldering extension wires on, I simply make up a little jumper harness .....


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The regulator end gets 4 individual spades that are plugged into the VR115 plug .....


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To keep them in place, I install a couple cable ties .....


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On the harness end, a matching plug to the harness is installed and I make the transition from 4 wires to 3 by combining the red (or orange) and yellow wires on one crimp .....


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The extension harness is routed behind the battery box up to the regulator harness plug .....


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And that pretty much covers it. Here's a list of some VR115 substitutes from other manufacturers, same regulator just under a different part number .....

GRX-528 Motorcraft (Ford)
VR 1010 NAPA Echlin
VR727 Wells
1V1033 Airtex
C622 AC Delco
VR-1760 Ace
VR291 GP Sorensen
R292 BWD
KVR179 Borg Warner

The silver one pictured above is the NAPA VR 1010 .....


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This section discusses updating your rectifier. It's also written by 5twins.

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Alright, now let's talk about rectifiers. As mentioned, on the '79 and older bikes, it's a separate component, but it's basically the same thing that is built into the combined reg/rec used on the '80 and newer models. A rectifier is a rectifier is a rectifier, they all basically do the same thing - convert AC current to DC current. There's no need to pay big bucks for a motorcycle or auto specific one, a much lower cost one from the electronics world works just fine. All you need to do is make sure it's a three phase type and it's amp rating is high enough to handle the 650's amp output, which isn't much, lol. According to the shop manual, it only puts out about 11 amps max. So, we usually choose a rectifier rated at 25 to 35 amps. You will find many rated much higher, like 50 to 100 amps, but they cost more and it's way over-kill. A favorite and one that has a very good track record is the $10 unit from Windy Nation like Jim used in his combined reg/rec above. I've used the same one but as a stand-alone unit. The rectifier gets hot in operation so you'll want to mount it on something to act as a heat sink. A little square plate of aluminum is fine. I got a bit fancier with mine, and it's probably over-kill, but I used a section of heat sink from an old computer .....

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The wiring connections are marked on the side, and you can also see a little of the heat sink compound I applied squeezing out. I also incorporated a little clamp for the wiring loom into the mount for the hanger bracket .....


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Here's a better explanation for the wiring .....



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Now, this isn't your only option. As I said, there are many rectifiers out there that would work. Some have used this low cost Chinese eBay offering. The draw to it probably (besides the low cost) is it comes mounted to a heat sink already. All you need to do is wire it and make a hanger bracket for it, as I've done here .....


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I also found it pretty easy to replicate the flat sided mounting bolt of the original. I just sliced the side off the new bolt with a cut-off wheel in a Dremel .....


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Then it can be easily hung off the bottom of the battery box in the original location .....


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One little "gotcha" you may encounter is that the spade terminals are too wide to accept the usual 1/4" female spade crimp. But that's no big deal, they're easily cut down, again using the cut-off wheel and Dremel .....


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Wiring info is clearly marked on the side but here's a labeled pic .....

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But I should mention that a couple guys have had issues with these, had them crap out in a short time. But they've worked just fine for others. Guess it's the chance you take buying cheap Chinese stuff.

Yet another option is a rectifier from another Yamaha model. A more modern fully enclosed unit was used on several, specifically some of the XS360, XS400, RD400, and XS500 bikes .....

https://www.partzilla.com/product/y...?ref=b17428832a11b6afaae5fab458086d9a277862ff

This is a nice looking little unit and all you need to do is change the plug from the female type that comes on it to a male type .....



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Very useful "how to"! When routing the wiring off the top left, the original rectifier leads (black, red and 3 white) might be just long enough to reach the new rectifier without having to extend them, if they were clipped off a junk OEM unit right where they come out of its case to keep them as long as possible. Even so, they might not be long enough to be able to clamp the wire bundle to the base plate as well - someone else who builds one would have to measure and report. If this was the case, there is enough room "fore and aft" behind the frame backbone to mount the baseplate with standoffs to move it rearward somewhat. If you wanted the new regulator to be separable, it can be wired through a 2-pin, 2.8mm latching connector such as CycleTerminals number SC1102.
 

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Just want to give a huge thanks to Jim for answering all my questions on building and wiring this! Just got done hooking it all up and am proud to say that it works beautifully! No more boiling my battery from using the cheap Chinese reg/recs lol. This setup now caps it at 14v while riding. Thanks again Jim!!!
 

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I wonder how warm the plate gets with the 3ph rectifier and the VR mounted to it. Where are you going to mount it in the '80- Rec/Reg spot in front of the swing arm or under the battery where the Electronic iggy was or ?
 
I wonder how warm the plate gets with the 3ph rectifier and the VR mounted to it. Where are you going to mount it in the '80- Rec/Reg spot in front of the swing arm or under the battery where the Electronic iggy was or ?
I mounted mine in it's original location. On my first ride with it... about an hour and a half, it wasn't any warmer than the tube it mounts to. No problem holding your hand on it.
 
So, I've been getting quiet a few PM's lately about how I wired my reg/rec on the 80SG resto. I know there's a lot of info on this site already about this...but most of it's in comments and not in it's own thread... at least I haven't found one. So here's a thread to put all the info in one place.
First up, the type 'A' regulator. Here's the schematic to wire it up for a direct replacement for the 80 and up XS650 using the Windy Nation 30 or 35A rectifier and the Fiat VR-794 regulator

I'm I understanding correctly that you are grounding the regulator through the aluminum plate to the frame? If so have you had any issues with this?
 
I'm I understanding correctly that you are grounding the regulator through the aluminum plate to the frame? If so have you had any issues with this?
Yes... and no issues. There is no ground wire, just a ground tab that lays under one of the mounting lugs. Here's a zip tie stuck between the lug and the ground strap.

IMG_20200704_201433.jpg
 
I Just reused the stock connector by backing the pins out. Got mine installed and working but I would like to warn those who do this in the future. if you are running the stock airboxes, make sure that your leads from the Reg/Rec are long enough to get the backside of the air box. I Had to remake my leads because they were getting crushed behind the airbox.
 
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Is there an alternative part number because VR-794 is bringing up a regulator that’s $160+ and doesn’t look anything like the one you posted about.

I have found R914 and VR-170 that look pretty similar.
 
Is there an alternative part number because VR-794 is bringing up a regulator that’s $160+ and doesn’t look anything like the one you posted about.

I have found R914 and VR-170 that look pretty similar.
Not sure where you're searching... when I click on my link in comment #1 I see this.... less than 15 bucks shipped.

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can you post a URL to that? When I click the above link in post #1 it’s an old listing and you can no longer buy it.
That is from that link. Says it's sold. I scroll down the page and that's the first thing it comes to after that. Just noticed it says 0 available. Perhaps that's why it's not showing for you?
 
Hows 8 bucks Canadian sound.... Link.
Not sure what shipping will be. If you order it, please let us know about that.


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