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Regulator / Rectifier Upgrade (SH847)

25 posts Started 23 Apr 2023 Last recovered post 2 Jun 2023 Wayback Machine snapshot 19 May 2025

#1

The Problem:

The 5th gen VFR’s are known for having questionable Regulator Rectifiers (RR) that can suffer from overheating (other gen VFR's also suffer from the same issue).

One preventative step that can be taken is to replace the RR with a mosfet (FH020AA) or series (SH847) RR.  I went with the SH847 option as I want to run LED’s and I think this would be the best option for that.

Not all bikes suffer from overheating, however I decided to do it as a preventative step on my 5th gen.

Parts/Tools Required:

Parts List:

  • ·       Shindengen SH847 RR Kit from roadstercycle.com.  It comes with crimp and solder type connections.  Mine only came with the crimp style connectors, so I used them.  For 5th Gen VFR’s you need 12” battery cables and the default stator cables are 24” and need to be cut to length.
  • ·       4 Way Mounting bracket from roadstercycle.com (Optional)

Tools:

  • ·       Crimping tool with insulated crimping capability like:

[image: 14.thumb.jpg.3d293b1f155aac140cdaabffe82bf453.jpg]

  • Soldering iron (if you decide to use the solder connections)
  • Hex tool for mounting the bracket (I can’t remember the exact size)
  • Screwdriver + Spanner (10mm) + Socket.
  • Heat gun or hairdryer
  • Electrical Tape & Cable Ties (Optional)
  • Tools required for removal of Rear Cowl

Steps:

1. Remove the Seat.

2. Remove the rear Grips

[image: 15.jpg.9762f7e363158df89935457e61ba6ae8.jpg]

3. Disconnect rear turn signals and brake lights.  Turn them counter clockwise to loosen.  It can be tricky to get a good grip, so take your time.

[image: 16.jpg.73da22c4d865800bb5768daa62bb9ae4.jpg]

4. Remove the rear Cowl.

[image: 17.thumb.jpg.9d6088a83b4b0b12a3295b8e5e7db593.jpg]

5. Label the lights as they are left dangling (Optional).  Remember to remove when reinstalling

[image: Lights.thumb.jpg.2e3d515916bf99b7318a8fd9a4ebbe7d.jpg]

6. You can now see the old regulator Rectifier.  Remove this by removing the 2 bolts.  On my bike, 1 could be removed by the front bolt, the other had a nut that needs securing as you remove the bolt.  Access is great though so you should have no problem.  Tape up the old power connector, you wont need this.  You will be left with the following:

[image: 1.thumb.jpg.3a10347f16f250580d2bb8b48175d1d5.jpg]

7. I used the 4 way mounting bracket to mount in the stock location.  You will be required to cut off one of the corners and file it smooth, like so:

[image: 2.thumb.jpg.e34efb057cf2761c03ad81ec7f94c3e3.jpg]

8. Mount the bracket using the supplied hex screws.  I had to use a bolt on the rear of one of them.

[image: 3.thumb.jpg.90f48a51b109c1f7eac36f04d90e7c18.jpg]

9. Mount the new RR onto the mounting bracket.  The cooling fins do not have to be parallel to the airflow for this type of RR.

[image: 4.thumb.jpg.8f584912f5eb822607f6118b1f23272f.jpg]

10.  At this point you should check clearances by loosely reattaching the upper cowl.  If it does not fit, move the mounting bracket as required, or relocate to a different location.

11. Plug in the new cables.

[image: 5.thumb.jpg.18f0e4d8ab6e0eae578f5e0e4959add2.jpg]

12. Cut the old stator plug.

[image: 6.thumb.jpg.bc5ee6030643d2c15cf9d4518f52c0fc.jpg]

[image: 7.thumb.jpg.0285c4b080637101b76ab2d498b46e06.jpg]

13. Strip a small length off each stator cable

[image: 8.thumb.jpg.ff5d8c79152ee033bcf26cce552d87b4.jpg]

14. Slide the crimp connector onto one of the cables, if using the crimp style connectors.  Otherwise use the solder type connectors.

[image: 9.thumb.jpg.266c5c7abdfca1ad1436597a1abc4038.jpg]

15. Crimp between the midpoint and the end point.

16. Strip a small length off the new stator wires.  They will need to be cut to length first.  I left a little spare, just in case.

[image: 10.thumb.jpg.3d796469d3bfcdfa54dfdf2d4f0396a5.jpg]

17. Slide this into the other end of the crimp connector and crimp between the midpoint and end point.

18. Do this for all 3 stator cables

[image: 11.thumb.jpg.92e0addf184cdff9b5ed02d300eb9a14.jpg]

19. Test by starting the bike and checking voltages, it should be 13V’s at idle and over 14V @ 5k rpm.  If all is ok, continue.

20. Use the heat gun or hairdryer to heat the heat shrink around the crimp connectors.  Use tape around them (Optional).

[image: 12.thumb.jpg.3a5dd3a4732e2f75df03cab3dbef6a86.jpg]

21. Cable tie the cables out of the way (optional)

[image: 13.thumb.jpg.5b688f33e4475cca216a7e5e9207d9d8.jpg]

22. Reinstall the upper Cowl in reverse order.

#2

Thanks for write-up!

Did you happen to measure temp of old RR?

Try touching this RR after a ride. 🙂

#3

@toreckman -- Suggest adding a digital voltmeter up front to watch the behavior of the SH847. A couple members reported some odd voltages at idle and wouldnt recover with revs. 

Also, keep an eye on the crimp connectors. Have seen some burnt over time... 

Nice write up..... 

:beer:

#4
19 minutes ago, mello dude

@toreckman -- Suggest adding a digital voltmeter up front to watch the behavior of the SH847. A couple members reported some odd voltages at idle and wouldnt recover with revs. 

Also, keep an eye on the crimp connectors. Have seen some burnt over time... 

Nice write up..... 

:beer:

I have a voltage meter installed, so I will be keeping an eye on it.

Do you have any links to stories of burnt crimp connectors/odd voltages?

I would be very interested in reading up on that.

#5
37 minutes ago, DannoXYZ

Thanks for write-up!

Did you happen to measure temp of old RR?

Try touching this RR after a ride. 🙂

Hopefully it doesn't get as hot as the old one.

#6
27 minutes ago, toreckman

I have a voltage meter installed, so I will be keeping an eye on it.

Do you have any links to stories of burnt crimp connectors/odd voltages?

I would be very interested in reading up on that.

@vfrcapn has good photo of crimp connectors good and crispy...

---- 1st choice is going to a solder connection. But if a connector is a gotta have, a Metripack 630 is the one to have. Its designed for high current applications. 

http://www.cycleterminal.com/metri-pack.html

Same for the fused to pos battery side connection......

http://www.cycleterminal.com/fuse-boxes.html

Odd voltages... Cogswell posted on that one, commenting with another member with the same situation. (Cant remember the name) 

#7

According to the professional motorsports wiring guys, the problem with solder connections is that solder embrittles the wire where the solder meets the rest of the un-soldered wire, creating more of a weak point than does a properly crimped butt connector.  Both solder joints and crimp joints have to be done correctly and protected from the environment with adhesive-lined shrink tubing, but from what I have been reading over the past couple of years, toreckman's got it right with the heatshrink-crimps.  Ideally, the three crimps would then be sealed within a long piece of adhesive-lined heatshrink, rather than leccy tape, however!

Btw, whilst you're in there, you should see to that Big Orange Connector with all the GNDs.  Especially if it is exposed to the environment like that it will only be a matter of time before corrosion begins to form on the terminals.  A couple of years ago I would have said to solder them all together, but...  :happy:

Ciao,

JZH

#8
1 minute ago, JZH

According to the professional motorsports wiring guys, the problem with solder connections is that solder embrittles the wire where the solder meets the rest of the un-soldered wire, creating more of a weak point than does a properly crimped butt connector.  Both solder joints and crimp joints have to be done correctly and protected from the environment with adhesive-lined shrink tubing, but from what I have been reading over the past couple of years, toreckman's got it right with the heatshrink-crimps.  Ideally, the three crimps would then be sealed within a long piece of adhesive-lined heatshrink, rather than leccy tape, however!

Btw, whilst you're in there, you should see to that Big Orange Connector with all the GNDs.  Especially if it is exposed to the environment like that it will only be a matter of time before corrosion begins to form on the terminals.  A couple of years ago I would have said to solder them all together, but...  :happy:

Ciao,

JZH

Thanks for the input.  I'm going to sound like an idiot, but what is that orange connector actually for? 😕  I have been wondering since I saw it  😂

I am still in the middle of upgrading/restoring my vfr, so nothing is final yet.  I have a can of silicone, I could coat the tape, to keep water out?  Or is there anything else i could use to wrap around them?

#9

Orange combines multiple ground-wires for different circuits together. Corrosions here can cause ground-loops where each circuit may have different voltage drops from batt +pos. Results in a 3rd circuit that flows the difference. On newer models, Honda went to ring-terminals and bolted them together for better contact-pressure and keep out corrosion.

Only problem with solder is if you use so much it wicks out past end of terminal. That's only case where it's different than crimp-only. Straw-man really as no one uses that much. And physical loads on wires don't even come close to fatigue-limits (except in case of large transitions). Just a little dab at tip to seal wire-end from moisture being wicked into wire and causing green/black wire disease. And fills air-space between strands to improve conductivity with much larger contact surface area.

Most of wiring issues I've seen are from using generic crimps with generic squashing crimpers. Transition from small wire to large crimp causes much larger stress-riser than soldered connections.


[image: uc?export=download&id=1r0wMpb1IvRlVWEA2J]

In order for crimps to even come close to their potential (like used in those comparisons), you need a matching crimping frame+die +terminals system. Where die generates a W or hexagon shaped crimp which squeezed OD inwards to remove as much air from between wire-strands as possible. But not so much squeeze it takes metal of terminal past plastic/yield limits. I use these to build my harnesses

https://www.newark.com/c/connectors/connector-tools-accessories/crimp-tool-dies?brand=amp-te-connectivity

To make proper crimps like these:

[image: uc?export=download&id=1HAS38doAjPsZb9VTp][image: uc?export=download&id=15K5-u79va7Ljhkyk_]

Then if you add a little dab of solder to seal end, but not so much you see it flow past crimp into strain-relief, that's even better! 🙂

Here's guidelines to making good crimps. Without proper matching crimper die+terminal system, best to back it up with solder.
https://drive.google.com/file/d/1rl2jsBrLlF_GMpFynaE21_X0bIfOdWr3/view?usp=sharing

#10

Here's example of brand-new crimped connectors that burned up as well.

[image: uc?export=download&id=1TfhiZ7Cs0DmFDF20G]

Other than being new, it is not an improvement over Honda's selection of bare-brass uncoated connectors.

[image: uc?export=download&id=1UVtIxtxoY5yHMNZjT]
Highest-capacity 1/4" spade terminals I could find is rated for 24a. Honda uses that in many 30a circuits (starter-solenoid). Due to lack of contact surface-area, it heats up and burns well before hitting max-rating when tiniest amount of corrosion develops.  Soldering lowers temps significantly at wire to terminal joint and keeps out corrosion, but you still have limited contact surface-area between male-female connection.

Ultimate solution is this:

[image: uc?export=download&id=1pXqm5Wih-R0X0V9_z]
I did this on my RC24 10-yrs in. It's held up fine for past 27-yrs without any signs of overheating, much less burning. It's done this way in pro-motorsports (F1/MotoGP), military and aerospace applications for performance, reliability and durability. Having worked in 2 of these fields, NASA & Army, I can confirm benefits.

[video: https://www.youtube-nocookie.com/embed/uhzXRIj5FaY?feature=oembed]
#11
1 hour ago, DannoXYZ

Other than being new, it is not an improvement over Honda's selection of bare-brass uncoated connectors.

🤣

Really good info, thanks.  That's a good job on those connectors.

Can a "less perfect" splice hold up at all, if properly crimped?  The ones supplied that I used are these.

I will keep an eye on the crimps I used, when I get the bike fired up.

I still have a few things to finish before its ready though.

#12

It should be fine. You've got tinned-wiring that's corrosion resistant. And nice seal with adhesive heat-shrink.

Only issue would be max-power rating across that connection. But SH847 only transmits as much as needed, rather than 100% of stator-output fulltime like factory RR. So you're looking at lots less current going through that connection. Some related topics I've found:

http://v4musclebike.com/forums/showthread.php?t=25778 <-- actual current measurements
https://www.cbrxx.com/threads/actual-stator-temps-sh847.49533/ - temp testing
https://www.douglasvanbossuyt.com/category/hobbies/motorcycle/ - more temp tests
https://www.cbrxx.com/threads/sh847-series-regulator-rectifier-install.42754/
https://www.kawasakiversys.com/thre...-shunt-star-delta-technical-info-2017.222367/
https://www.vstrom.info/Smf/index.php?topic=20426.0
https://www.vfrdiscussion.com/index...-new-to-vfrd-from-new-jersey-need-helpadvice/
https://www.accessnorton.com/NortonCommando/biting-the-bullet-on-charging-system.28810/page-3
https://www.apriliaforum.com/forums...t-step-wires&p=2845062&viewfull=1#post2845062
https://www.triumphrat.net/threads/charging-system-diagnostics-rectifier-regulator-upgrade.104504/
https://www.thumpertalk.com/forums/topic/1320648-stator-trouble/
https://www.createfixshare.com/articles/drz400-sh775-regulator-rectifier-upgrade/

#13

Thats lots of bedtime reading. 😄
At a quick glance through some of the temperature tests, there seems to be a nice drop with the sh847.

#14

I just upgraded to the sh847 and a new 6G stator for my '99, and a lithium battery.

Stator few months ago:

[image: image.jpeg.4c02c698558a4f8e6ad9fa22eed53b3d.jpeg]

Stator connector in '09.

[image: image.jpeg.f5a825bf081eff5f9437403485be0adf.jpeg]

Did the crimp connectors and simply twisted/shrink wrapped the other end, eliminating the Honda connector.

[image: image.jpeg.a52bd3e762bf6e4aecba6757b2a019a9.jpeg]

18 months later:

[image: image.jpeg.5129848a6130fa8a8ccfd4efea24bceb.jpeg]

Respliced and soldered those burnt connections, the spade connectors at the r/r were toasty as shown above so I tried once more with new crimp connectors. About 15 months later:

[image: image.jpeg.cadc5a901a3ee0123fd3e48348288cc7.jpeg]

Finally took those out and soldered everything, no connectors. Ran fine for the last 10-11 years like that until the stator started going.

Lesson learned on those cheap connectors for higher amp circuits.

#15

I would not use spades or even consider a connector for the stator wires.  Crimp splice connector OK, but solder it as well and heat shrink over it.  I would also take R/R wires direct to battery and not use the bike's wiring via the starter relay, etc.... but do put a 30 amp fuse in that circuit.

#16
13 hours ago, DannoXYZ

It should be fine. You've got tinned-wiring that's corrosion resistant. And nice seal with adhesive heat-shrink.

Only issue would be max-power rating across that connection. But SH847 only transmits as much as needed, rather than 100% of stator-output fulltime like factory RR. So you're looking at lots less current going through that connection. Some related topics I've found:

http://v4musclebike.com/forums/showthread.php?t=25778 <-- actual current measurements
https://www.cbrxx.com/threads/actual-stator-temps-sh847.49533/ - temp testing
https://www.douglasvanbossuyt.com/category/hobbies/motorcycle/ - more temp tests
https://www.cbrxx.com/threads/sh847-series-regulator-rectifier-install.42754/
https://www.kawasakiversys.com/thre...-shunt-star-delta-technical-info-2017.222367/
https://www.vstrom.info/Smf/index.php?topic=20426.0
https://www.vfrdiscussion.com/index...-new-to-vfrd-from-new-jersey-need-helpadvice/
https://www.accessnorton.com/NortonCommando/biting-the-bullet-on-charging-system.28810/page-3
https://www.apriliaforum.com/forums...t-step-wires&p=2845062&viewfull=1#post2845062
https://www.triumphrat.net/threads/charging-system-diagnostics-rectifier-regulator-upgrade.104504/
https://www.thumpertalk.com/forums/topic/1320648-stator-trouble/
https://www.createfixshare.com/articles/drz400-sh775-regulator-rectifier-upgrade/

Don't listen to these guys, this is all you need:               😉

[image: IMG_7895.jpeg]

Seriously, that's just my level of electrical knowledge! We have so many experts on this forum, myself obviously not being one of them. I only bought a voltmeter a few years ago because that's how Grum started every problem solving post.

#17
35 minutes ago, raYzerman

I would not use spades or even consider a connector for the stator wires.  Crimp splice connector OK, but solder it as well and heat shrink over it.  I would also take R/R wires direct to battery and not use the bike's wiring via the starter relay, etc.... but do put a 30 amp fuse in that circuit.

The kit comes with fused direct wiring on the battery side.

@vfrcapn: how many miles were on your bike when your original stator plug got that fried?

After 30k miles, mine had no damage, except a tiny bit of yellowing on 1 of the pins:

[image: IMG_20230425_180439_1.thumb.jpg.5821b813df94a951defc8e4c781c44c0.jpg]

#18
toreckman, 4/25/2023 at 10:10 AM

The kit comes with fused direct wiring on the battery side.

@vfrcapn: how many miles were on your bike when your original stator plug got that fried?

After 30k miles, mine had no damage, except a tiny bit of yellowing on 1 of the pins:

I was somewhere around 70K miles when that original plug burnt out, second r/r however, original r/r replaced as preventative measure iirc.

#19

Interesting. how come some bikes fair better than others?

Is it variation in the oem stators/RR's installed? Or climates etc.?

I have seen some fried with less than 20k miles.

#20
8 hours ago, toreckman

The kit comes with fused direct wiring on the battery side.

@vfrcapn: how many miles were on your bike when your original stator plug got that fried?

After 30k miles, mine had no damage, except a tiny bit of yellowing on 1 of the pins:

[image: IMG_20230425_180439_1.thumb.jpg.5821b813df94a951defc8e4c781c44c0.jpg]

That connection is on a path to destruction! Glad you've detected it early enought. Take rayZerman's good above advice and get rid of the stator connector.

"I would not use spades or even consider a connector for the stator wires.  Crimp splice connector OK, but solder it as well and heat shrink over it."

#21
8 hours ago, toreckman

The kit comes with fused direct wiring on the battery side.

Glad you mentioned Fused.

NEVER use cheap and very nasty Auto Reset Circuit Breakers!

#22
15 hours ago, toreckman

Interesting. how come some bikes fair better than others?

Is it variation in the oem stators/RR's installed? Or climates etc.?

I have seen some fried with less than 20k miles.

The poor-ish OEM regulator mostly fails first or the connectors get hot/oxidize/melt.  If the stator's output is no longer being managed properly by the wiring/regulator, stator will overheat and ultimately fail..... taking care of things regulator/connector/wiring related will save the stator the vast majority of times.  Prevention is the key.

#23

Hi

Just to share the same happened to me. My OEM RR died on 2021, I've ordered a Mosfet and still this happened.

I was ridding felt the heat on my leg stopped and saw smoke coming from the fairing.

I will order another RR now from below website per @Mohawk advise, and I guess the big lesson learned here is ditching the connectors and just Solder the Wires.

  https://www.electrexworld.co.uk/cgi-bin/sh000001.pl?WD=vfr800&PN=RR53%2Ehtml#SID=439 

[image: BD7277E5-4609-47DB-B9FD-37E12118ABD0copy.thumb.jpeg.c0575f01841ccbbf56163403ff6d5273.jpeg][image: 04BF171E-730C-41CF-AA2B-B69ED653088Bcopy.thumb.jpeg.3bb7a3d7e1da71ac5e1f6066fc8ba952.jpeg]

[image: IMG_3381 copy.jpg]

[image: IMG_3386 copy.jpg]

[image: IMG_3387 copy.jpg]

#24
22 minutes ago, Resina

Hi

Just to share the same happened to me. My OEM RR died on 2021, I've ordered a Mosfet and still this happened.

I was ridding felt the heat on my leg stopped and saw smoke coming from the fairing.

I will order another RR now from below website per @Mohawk advise, and I guess the big lesson learned here is ditching the connectors and just Solder the Wires.

  https://www.electrexworld.co.uk/cgi-bin/sh000001.pl?WD=vfr800&PN=RR53%2Ehtml#SID=439 

per Mohawk advise, and I guess the lesson learned here is ditching the connectors and just connected the wires

[image: BD7277E5-4609-47DB-B9FD-37E12118ABD0copy.thumb.jpeg.c0575f01841ccbbf56163403ff6d5273.jpeg][image: 04BF171E-730C-41CF-AA2B-B69ED653088Bcopy.thumb.jpeg.3bb7a3d7e1da71ac5e1f6066fc8ba952.jpeg]

[image: IMG_3381 copy.jpg]

[image: IMG_3386 copy.jpg]

[image: IMG_3387 copy.jpg]

I skipped the stock connenctor and wired it directly to the stator as a lot of people here have said and it's been smooth sailing since. 

#25
1 hour ago, Resina

Hi

Just to share the same happened to me. My OEM RR died on 2021, I've ordered a Mosfet and still this happened.

I was ridding felt the heat on my leg stopped and saw smoke coming from the fairing.

I will order another RR now from below website per @Mohawk advise, and I guess the big lesson learned here is ditching the connectors and just Solder the Wires.

  https://www.electrexworld.co.uk/cgi-bin/sh000001.pl?WD=vfr800&PN=RR53%2Ehtml#SID=439 

[image: BD7277E5-4609-47DB-B9FD-37E12118ABD0copy.thumb.jpeg.c0575f01841ccbbf56163403ff6d5273.jpeg][image: 04BF171E-730C-41CF-AA2B-B69ED653088Bcopy.thumb.jpeg.3bb7a3d7e1da71ac5e1f6066fc8ba952.jpeg]

[image: IMG_3381 copy.jpg]

[image: IMG_3386 copy.jpg]

[image: IMG_3387 copy.jpg]


I would not order the regulator that you linked. I'd order a SH847 from www.roadstercycle.com or Suzuki directly.

That regulator you linked is very low quality and should not be used from my experience. I have seen them fail. They also still cause pre-mature stator failure due to the nature of MOSFET technology. Series rectifiers actually keep the stator cooler! A cooler stator lasts many many more miles.

End of thread · 25 posts recovered Wayback Machine snapshot 19 May 2025