The personal and professional website of Douglas Van Bossuyt
I took my Honda Pacific Coast PC800 out for a long ride through the hinterlands of Monterey County today. I went through Carmel Valley and over the top to Greenfield before heading further east on some new-to-me roads. I finally returned home later in the day. It was a thoroughly enjoyable ride dancing between fog and sun.
This page describes installation of a Shindengen SH847 series regulator/rectifier (R/R) on a 1997 Honda Pacific Coast (PC800). Results of various tests performed after installation are included.
Editor’s Note: The following information comes entirely from fellow PCer Seth. He did excellent research and produced a wonderful writeup of how to install a series regulator rectifier (R/R) on a Honda Pacific Coast.
This page describes installation of a Shindengen SH847 series regulator/rectifier (R/R) on a 1997 Honda Pacific Coast (PC800). Results of various tests performed after installation are included.
The R/R performs two functions: it rectifies the three-phase AC output from the stator to provide DC and it regulates the output to avoid overcharging the battery. The stock regulator is a shunt design which operates by short circuiting the stator windings when the battery is fully charged. The excess power is dissipated as heat by the R/R. The SH847 is a series regulator and operates by disconnecting the stator windings when the battery is fully charged.
Note: The SH847 isn’t cheap. Towing a trailer over The Mighty Mac up to The Very Boring Rally in Duluth, MN, without a charging system makes it seem worthwhile.
Having replaced all of the lights on Winglet, a 1997 Honda Pacific Coast (PC800), with LEDs there is plenty of power available for farkles: driving lights, heated lederhosen, Bushtec trailer, … . That is not what Mother Honda had in mind when the charging system was designed. The LED conversion greatly reduces the electrical load and shifts more responsibility to the regulator.
The stock R/R and, to a lesser extent, the stator are considered (by owners) to be consumable parts. The first is rather easily replaced. The second involves opening the crankcase and is, at best, a nuisance. (Been there, done both repeatedly, didn’t get the shirt. At least the engine doesn’t need to be removed from the frame like ‘oldWing’s.)
The series R/R design allows the stator voltage to rise, but reduces the load and the heat produced by the stator. High voltage is related to insulation breakdown, but so is elevated temperature. In my judgement the voltage (About 70VAC open cicuit, IIRC.) is not sufficient to significantly shorten the life of the stator and the lower temperature should increase the life. (Then there is thermal cycling causing physical damage to the stator and … .)
The plan is that this should be the last R/R and stator that Winglet needs. (This is what authors call “foreshadowing”.)
It’s big, but fear not. There is a splendid place to hide it if you haven’t tucked an air horn or other farkle in the right fairing protector. It mounts securely to the frame within the structure of the fairing protector, though it does not use the frame as a heatsink. The weathertight connectors face aft to reduce exposure to road spray. Engine heat and exhaust from the radiator ductwork are not problematic. Ideally the cooling fins would be oriented from front to back to provide better airflow, but there isn’t sufficient space to rotate the R/R with the connectors and cables attached.
Tip: Click on any image to open a larger version in a new browser tab.
Despite considerable hunting, I have not been able to find a comprehensive specification sheet for the SH847 from Shindengen. The following specifications have been cobbled together, but are certainly not guaranteed.
| Property | Value | Note |
|---|---|---|
| Width | 120mm | 100mm between mounting hole centers. |
| Length | 135mm | Plus mating connectors and minimum bending radius for wires. |
| Thickness | 40mm | About 1 9/16″. |
| Current | 30A | Average @ 40°C (104°F) with no airflow. |
| “ | 37A | With 1 m/s (2 1/4 mph) airflow. |
| Peak Current | 50A | PC800 alternator maximum output is 360W or about 30A. |
| Protection | Voltage & Temperature |
Sources of supply are shown, but feel free to shop around.
Note that installation of the SH847 leaves the original R/R and wiring in place. You can disconnect the SH847 and reconnect the stock R/R if there is some reason to do so, e.g. the frame is cold.
NB: Do NOT run the engine with both R/Rs connected to the battery at the same time.
You don’t want to find out if the overvoltage protection circuits in the two regulators get into an argument.
I don’t think they will, but with the price of Magic Smoke these days … .
Winglet was ridden with various electrical loads. It didn’t matter. The new R/R became lukewarm at most, but never hot. The stock R/R would have removed fingerprints in an instant.
The minimum load was without any accessories and all of the lights replaced with LEDs. With the stock R/R this would result in the maximum amount of current being shunted and thus the maximum heat generated. Aside: At idle with stock lamps and the brake lights on the battery would have been discharging. With LEDs that is not the case.
The following measurements were made with the ignition on and the engine not running. (For perspective, the stock headlight bulb draws 4.9A/5.4A.)
| State | Total Load | Note |
|---|---|---|
| Headlight and running lights. | 1.91A | |
| + Driving lights on high. | 2.84A | Denali D2 LEDs. |
| + Brake lights. | 3.35A |
Maximum load was with a heated vest (about 45W), driving lights, Bushtec trailer and various minor accessories. (All of the trailer lights have been replaced with LEDs with the exception of the license plate lamp. It has wires soldered to the bulb and the bulb is glued in place!) Engine temperature was allowed to rise sufficiently to turn on the cooling fan.
The misfortune that followed provided an opportunity. Not long after installing the new R/R the Rick’s Motorsport Electrics stator installed about 15 years earlier developed a short to ground. (The original stator lasted about 8 years.) An ElectroSport stator was purchased and the experiment was planned. Various resources on the Internet suggested that a shunt regulator reduces the load on the stator when it shorts the windings. (Did you know the word “gullible” isn’t in the dictionary?) It seemed like a good time to get some objective data on stator temperatures under various conditions using shunt and series regulators.
Possibly applicable reading: Facts about shunt-based regulators.
Possibly applicable viewing: “Turbo Encabulator” the Original.
First, do no harm. I know that the stator is an unhealthy place with hot engine oil, hotter windings and machinery with a low tolerance for loose bits bobbing around. All of the materials going into that environment had to tolerate chemicals and heat. As a SWAG I chose 200°C (392°F) as a target temperature limit. The materials I obtained I dubbed close enough:
Did you catch it? I didn’t. I soldered the wires to the RTD with an 800°F tip in the soldering station. Applied the conformal coating and allowed it to cure. Put the heat shrink tubing on and cranked up the Milwaukee hair dryer to shrink it … . Shrink temperature 620°F. 60/40 Sn-Pb solder melts at 370°F. D’oh! A little creative rearranging and I managed to get the solder to do its thing while the tubing shrank. (“Hats back on gentlemen, an idiot!”)
Aside: While taking soldering/brazing/welding classes I caused some confusion when I used the Milwaukee variable temperature heat gun to sweat solder 3/4″ copper pipe and fittings together.
A Littelfuse PPG102A6 Resistance Temperature Detector (RTD) was embedded between poles of the stator prior to installation. A Fluke 87 Multimeter was used in Min/Max/Avg record mode to capture the temperatures.
The wires were slipped through the jacket that protects the stator wires. Rather than make changes to the crankcase cover or seals I simply ran the wires out between the cover gasket and the cable seals. A generous dab of Permatex® Ultra Black® gasket maker is working nicely.
At idle the series regulator supplied <= 3.75A.
Started the engine and allowed it to idle until the fan cycled on and off. 72.6°F ambient temprature, 71°F stator before starting.
| No Regulator | Shunt Regulator | Series Regulator | Delta (Shunt – Series) | |
|---|---|---|---|---|
| Fan start: | 136°F | 198°F | 170°F | -28°F |
| Fan stop: | 139°F | 200°F | 171°F | -29°F |
| Maximum: | 140°F | 203°F | 173°F | -30°F |
The engine was then run at higher speed (~3K) and the maximum temperature noted:
| Shunt Regulator | Series Regulator | Delta (Shunt – Series) |
|---|---|---|
| 228°F | 212°F | -16°F |
Additional tests were run during sustained operation at highway speed.
The first test was run with the shunt regulator to give it the benefit of a cooler initial temperature. The second test was run with the series regulator.
| Shunt Regulator | Series Regulator | Delta (Shunt – Series) | |
|---|---|---|---|
| Maximum: | 288°F | 253°F | -35°F |
| Minimum: | 251°F | 240°F | -11°F |
| Average: | 272°F | 248°F | -24°F |
Conclusion: The series regulator lowers the stator temperature under all of the test conditions.
Here’s an option to replace broken mirrors on a Honda Pacific Coast PC800 motorcycle. Because the mirrors are no longer offered by the manufacturer, there are only a couple solutions to a damaged mirror. You can buy one off eBay or a similar site for a lot of money (as of April 2021, I’ve seen a set of mirrors sell for $500). You can contact Alex in Russia to have him resin cast new mirror plastic parts for you. You can contact Ruud De Greef via Facebook to buy 3D models of the PC800 mirrors and 3D print your own. Or you can contact Dolf Veenvliet for his version of 3D models for PC800 mirrors and also 3D print your own.
This post shows some of the info that I’ve pulled off of Facebook from Ruud De Greef. The original post is here.
I have no experience with the 3D printing files and I do not know if they are any good or not. If you buy the files from Ruud and they work well or they do not work well, please let me know so I can update this post.
Note that it appears only some of the parts are available for 3D printing so you’ll still need some parts harvested from your busted mirror.
Some people in the comments on the Facebook post mentioned that there were 3D STL files available several years back but I haven’t been able to find the files yet. I’m not sure if Ruud’s files are from the old STL files that a few have mentioned or if they’re created from scratch.
Here is something about the challenges of 3D printing old bike parts: https://www.fabbaloo.com/blog/2019/6/27/how-to-re-engineer-motorcycle-parts
Here is an old Reddit post that mentions someone at some point was 3D printing parts for the PC800. I haven’t been able to find any other information besides this: https://old.reddit.com/r/motorcycles/comments/63sup7/are_we_3d_printing_parts_of_our_bikes_in_the/dfwob04/
I have the mirrors from the PC800 transformed in a digital format. You can now print your mirrors yourself. The costs are 120 dollars for all files (see photos). IMPORTANT: you don’t get a real product ..only the files for your printer! Please send me a PM if interested. Printer volume needed: 200 x 200 x 250mm
Ruud De Greef
In 2023, Dolf Veenvliet developed 3D models of the PC800 mirrors. You can buy the models here. Dolf can also be reached via email at dolf@macouno.com. Some images of his 3D printed mirrors are available below. Note that he also has files for the PC800 crash guards which are getting in very short supply and the “Wong Wing” spoiler that can bolt on the back of a PC800 trunk.
The resulting printed part looks quite good on Dolf’s PC800. I suspect he’ll be out with more 3D printed parts for our beloved PC800s in the near future.
“Indie Ingenuity” posted his 3D printed mirror results on the PC800 Facebook group recently. He used Andrew M. in Austin, Texas who does local 3D printing (Plainfield Creations) but Andrew can also ship.
