New Regulator/Rectifier for the PC800

The other day I picked up a brand new Honda R/R via a friend from Rick’s Motorsport Electrics.  The old regulator/rectifier on the bike had been put on sometime in the last few years and came from a completely different bike.  It works but I thought I might as well put the real deal back on my bike.  The other R/R is now in my trunk as a spare in case of problem on the road.

The new R/R behaves differently than the other R/R.  Now my voltage stays at 14.1 volts no matter how much electrical heated clothing I have running (while the engine is above 3000 RMP).  At idle the bike stays happily in the 12 volt area and doesn’t dip below like the old R/R did.  I think this new one is a lot better than the old.  Hopefully I will get many thousands of miles out of it without incident.

14 Replies to “New Regulator/Rectifier for the PC800”

  1. So how would you rate the R/R change? I think I’ve got to do that to my bike pretty soon. Looks like you’ve got all the Tupperware off…not fun.

    1. I think the new R/R is fine. It reads about a half volt lower than the non-stock R/R that was on before. So instead of 14.5 like the old one read, the new one reads 14 or 14.1 at speed. When I load it down with a set of Gerbinger gloves and heated socks from Warm n Safe at 100% on my heat troller, it pulls the voltage down to 13.8 or 13.9 when at speed.

      The place I have my voltmeter attached isn’t directly hooked to the battery so it is probably a few tenths of volts below what the battery actually sees. I still carry the non-stock R/R in my trunk in case I run into problems.

      I also have noticed as the temps have gotten above 50 degrees in Oregon that the voltage meter will dip down to 13.8 or so when the engine is hot and I’m running at highway speeds. Guessing that’s the way the R/R responds to heat. I’m thinking about relocating it somewhere with cooler airflow or putting a dedicated fan on it for summer riding.

      The tupperwear disassembly and reassembly was pretty intense. I’m going to have to pop it off again soon. I’ve got a leak on the right side.

      If you aren’t aware, check out It’s the riders group for PC800s!

      1. I am trying to get my voltage reg off and i cant budge the phillip head screws …. dont want to strip the heads and i cant tell if there is a nut on the other side that i could break over…. have a 1990 and never had to replace b4….any suggestions?


        1. Hi Greg,

          Get a JIS screwdriver (you can order them from McMasterCarr such as: ). Or if you can find a JIS screwdriver bit, you can use an impact hammer/wrench to try and free the screw. As I recall on my ’89, thee nut behind the screw is welded to the frame.

          Have you put penetrating oil on the screw? Something like WD-40 or one of the many brands of miracle oil? Might be worth a shot… If worse comes to worse and you strip the thing out, you should be able to buy a tool that will help you get it out. Then you might consider zip tieing the new R/R in place rather than screw it unless you can recover the threads on the welded-on nut.

          My $0.02, anyway!



          1. I am now dubious about the McMaster Carr “JIS” screw drivers. The set that came to me recently appears to be more like JIS drivers but I don’t think they are actual, in-the-flesh JIS. I guess that means I’ll continue to search for real JIS drivers. 🙁

  2. The only Tupperware you have to pull is the left air vent if you like working in small spaces. If you want more room take off the side panel. The screw is under the air vent. As you pull the side panel off make sure that you help it from the back. If you pull the front out to far before pulling the back out you will brake the pin off.

    The whole job is 10 to 15 mins.


  3. My RR feels quite hot, including output wires, even with cool engine. Stator input is 50-70 vac but drops to 10-15 when plugged into rr. Could bad RR be loading it down? Stator is 5 years old, RR has never been changed. Got stranded last month, with new battery.

    1. There are relatively inexpensive R/Rs online. It wouldn’t hurt to give replacing your current one a shot. The worst that happens is you end up with a spare R/R like I did. 🙂

      1. Exactly, just updated mine with an “improved” model. 14.1 most time, was at 10 when I was “stranded”… now I have a spare in the trunk as well. Also replaced the Stator just to be safe.

        1. Ive gone through two regulators in two months Its a new bike to me. Could the fix be really as simple as checking the connections replace with a high quality R/R in a cooler location? Or is there some real good diagnosis i can do first .
          I purchased a super duty made in the R/ R and battery. Yet it only lasted 300 miles . it was at high RPMs . I just dont know.

          1. Howdy Edgar!

            You might want to run Pogo’s test on your whole charging system. And also Dave P’s R/R test to verify your R/Rs are good.



            And also as you said, check all the connections for corrosion and to see if you have any big voltage drops. There’s a hotwire mod to help if you’re having wiring harness issues (good voltage at the R/R but low voltage at the battery).

            It seems that often times an R/R dying is caused by the start of a problem in the stator. And replacing the R/R will make it okay for a while but will lead to another dead R/R sooner or later. But it often is the case that both the R/R and the stator need to be replaced together. However, Pogo’s test (see the link above) will determine that for sure for you.

            If you’ve got any other questions or whatever, please don’t hesitate to drop me a note on email ([email protected]), respond to this comment, post a message to the Facebook group ( or the Yahoo group We’re all really passionate about our PC800s and love to help others keep our quirky little tupperwear bikes on the road 🙂



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