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Discussion Starter #1
My r/r is toasted after 2 years and took the plug with it. The crappy wiring for the r/r that the dealership did and a weak battery seem to be the cause of the issue. I need a new r/r and have been reading through the site, but still haven't found a solid answer about placing the stock unit with a MOSFET rectifier.

These are the two options that I am looking into:

1. Search results for: 'ESR587'

2. http://roadstercycle.com/Shindengen%20FH012AA%20Regulator%20upgrade%20kit.htm

What is the upside/downside of the MOSFET?
 

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NEED WORK!
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Mosfet works in very different way to the oem setup.
Its a better way of regulating the voltage and a much better way of shunting (dischrging) the excess, which is the bit the oem fails...
I'd say go for it man!
If not look into the R1 solution now that the plug is also gone.. ;)
 

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I'll try to answer this with my limited, non-expert knowledge of electronics.

The XX alternator uses a permanent magnet rotor to generate power, rather than a dc-excited coil. This means that the stator is producing power whenever the rotor is turning.

The OEM R/R uses a voltage sensing circuit to control the operation of 3 SCR's (silicon controlled rectifiers), which are basically on-off switches. These are configured so that they are turned off when the battery & electrical system is below a set voltage, then turned on when the system voltage is above the set point. When they are turned on, they shunt the alternator output directly to ground to safely dissipate it. This means that the SCR's carry full current when they are operating, which makes then get quite hot. If this heat is not dissipated quickly enough, the SCR's begin to break down and eventually fail. When that happens, they stop shunting excess power to ground and allow it to flow unchecked into the battery which boils the electrolyte away and destroys the battery.

The mosfet R/R uses field effect transistors in place of the SCR's. Where an SCR is an 'on-off' switch, the FET is more like a dimmer switch. The control circuitry is able to vary the amount of power passed by the FET's to the battery to more precisely control the charging rate. I am guessing, not having seen a wiring diagram for a mosfet regulator, that there is no need for a shunt circuit as the FET's can reduce the amount of power sent to the battery rather than dumping the full current to ground. That should mean that there is much less heat created internally, provided the battery is in good condition and you aren't trying to draw excessive power from the alternator and through the FET's.

I don't really see a down side. Hope that helps.
 

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Flyin' Lo and Free
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Hey Billy, is your r/r the original plastic one or the aluminum finned type??
 

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Discussion Starter #6
Two years ago it was the original. This time around it was the finned one. I got it from regulatorrectifier.com 2 years ago.
 

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Discussion Starter #8
I ordered the kit from roadster cycle. I have to do a double check on the battery and stator, but for now it looks like its just the wiring/rectifier that got toasted.
 

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I ordered the kit from roadster cycle. I have to do a double check on the battery and stator, but for now it looks like its just the wiring/rectifier that got toasted.
You'll like it I have been running it for almost a year with no troubles so far.
 

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Discussion Starter #12
You'll like it I have been running it for almost a year with no troubles so far.
It looks to be a bit bigger than the stock. Did you keep it in the same spot? Did you keep the stock wire from the battery or use the replacement one?
 

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Yes I just modded a bracket that bolted to the stock one. Then I ran the wires off the regulator directly to the battery.
 

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Discussion Starter #14
Re: R/R - MOSFET or stock replacement? - Update: installed and short review

The kit showed up 3 days after ordering the kit (I ordered it on Sunday night, and it was here on Wed.). The connectors are a huge improvement over the original Honda connector. The unit itself is larger, but I was able to mount it basically the same way that I had stock finned one. I got everything wired up today and the voltage is back where its supposed to be. I tested the stator and the wiring for the rectifier and all came back good. Took a test ride with my heated vest and gloves... bike ran great and I was comfortably warm.

I think I am going to get my batter tested to make sure that its still in good shape. Its now been through two fried rectifiers.

Overall: 5/5
Packaging/shipping - 5/5
Kit contents - 5/5
directions - 5/5
Difficulty of install - install was easy as long as you can solder.
 

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Good idea jack is a very good gent if you have any questions about the regulator give him a holler. Spnt abnd houyr one satyrday answering questions for me before i made the purchase myself. He called me mind you.
 

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I've fitted the MOSFET reg/rec from Jaws. Comes with new connector and terminals. Fairly easy install if you have a good set of terminal crimps
 
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