Mosfet - cooler running stator. | GTAMotorcycle.com

Mosfet - cooler running stator.

G

gaihosa

Well-known member
Recently I had my stator fail. The insulation of the coil at the top position melted and the rest is history. I have gotten another stator and so far so good. Being tossing around some ideas on how to have it run cooler. I am considering a mosfet RR since there is one available for my bike from RMstator. By the sounds of it, the mosfet will run cooler but I can't really find anything about the stator running cooler. Some say it makes heat when not under load and others say the opposite. So my question is does a stator run cooler with a mosfet RR?

I have already changed my headlight to led long before this happened.

Also considering methods of cooling the stator such as a heat sink on the cover, oil line from the sump through the stator cover to dump oil on the stator, etc.
 
What year/model machine ?
I only ask because you may be trying to over solve your problem.
Engine oil typically runs between 120-150 degrees F, I doubt the stator by itself would ever get that hot.
Reg/rectifier location can also create overheat problems (see: GSXRs where its buried behind the radiator).
More information please.
 
Creeping the original poster's past posts suggests that this might be for a 2009 FZ6R. I think the engine (and stator) are same/similar to the earlier (pre-2006) R6. It looks like the voltage regulator is interchangeable with that of the R6. I don't know if the original-equipment voltage regulator is a mosfet design ... a lot of the newer ones are.
 
gaihosa said:
Recently I had my stator fail. The insulation of the coil at the top position melted and the rest is history. I have gotten another stator and so far so good. Being tossing around some ideas on how to have it run cooler. I am considering a mosfet RR since there is one available for my bike from RMstator. By the sounds of it, the mosfet will run cooler but I can't really find anything about the stator running cooler. Some say it makes heat when not under load and others say the opposite. So my question is does a stator run cooler with a mosfet RR?

I have already changed my headlight to led long before this happened.

Also considering methods of cooling the stator such as a heat sink on the cover, oil line from the sump through the stator cover to dump oil on the stator, etc.
Click to expand...

From what I've read, I think going from an analog R/R to a shunt MOSFET by itself just gets you more reliability. If you want cooler, then you would need to go to a series R/R, which opens the circuit rather than shunting it to heat. They're more expensive, though (about $60 US using Roadster Cycle's pricing).

Roadster Cycle Series R/R Kit
 
gaihosa said:
It is a 2009 fz6r. I found this on fortnine. https://fortnine.ca/en/ricks-motorsport-electrics-rectifier-regulator that's why I am considering this.
Click to expand...
... except that isn't a Mosfet regulator.
IF you want mosfet you want a Shindegen FH012AA or FH015AA or Fh020AA (Those all work the same, there is a SH775 and SH847 Shindegen that LOOK the same, but they are not Mosfet... BUT are a series unit, which helps)
AFIK the "Ricks" version of those are a knock off, the OEM version can be found on many current makes and models (I think I use the one off Can-Am ATVs, which I think (IIRC) is the cheapest one, about $225... the Yamaha part number is about $400, the Honda is somewhere in between. It is the same part. You can always find a used one on EBAY for $50.
I am NOT saying Rick's part is bad. I AM saying I have tried "knock offs" of those regulators and EVERY one of them failed. I haven't had a OEM one fail yet, the one in my 900SS is 7 years old.

A "regular" rectifier uses diodes only, which have "overhead", they use power to work (some more than others) and using that power they create heat.
A mosfet is a transistor that switches on and off in milliseconds, and when used in a rectifier circuit will have less "overhead" than diodes, therefore making less heat. They still "SHUNT" excess power to ground, but they do it more efficiently... MUCH more efficiently.
If you use one of those regulators you have to change the wiring harness to suit. A fairly simple process, but you'll need the Shindegen plug.
If you need help, get in touch, I've installed dozens of them. They're great, they work on one, two or three phase alternators, mount easily and so far, I haven't seen an OEM one fail
 
bitzz said:
... except that isn't a Mosfet regulator.
IF you want mosfet you want a Shindegen FH012AA or FH015AA or Fh020AA (Those all work the same, there is a SH775 and SH847 Shindegen that LOOK the same, but they are not Mosfet... BUT are a series unit, which helps)
AFIK the "Ricks" version of those are a knock off, the OEM version can be found on many current makes and models (I think I use the one off Can-Am ATVs, which I think (IIRC) is the cheapest one, about $225... the Yamaha part number is about $400, the Honda is somewhere in between. It is the same part. You can always find a used one on EBAY for $50.
I am NOT saying Rick's part is bad. I AM saying I have tried "knock offs" of those regulators and EVERY one of them failed. I haven't had a OEM one fail yet, the one in my 900SS is 7 years old.

A "regular" rectifier uses diodes only, which have "overhead", they use power to work (some more than others) and using that power they create heat.
A mosfet is a transistor that switches on and off in milliseconds, and when used in a rectifier circuit will have less "overhead" than diodes, therefore making less heat. They still "SHUNT" excess power to ground, but they do it more efficiently... MUCH more efficiently.
If you use one of those regulators you have to change the wiring harness to suit. A fairly simple process, but you'll need the Shindegen plug.
If you need help, get in touch, I've installed dozens of them. They're great, they work on one, two or three phase alternators, mount easily and so far, I haven't seen an OEM one fail
Click to expand...
But will the stator run cooler?
 
gaihosa said:
But will the stator run cooler?
Click to expand...
Rotor/stator feeds the regulator/rectifier, not the other way around.
The alternator's temperature is affected by the engine heat, not electrical feedback.
The only way you could lower that might be with an add-on oil cooler or a larger radiator.
Some other machines run a remote, fan cooled alternator to help lower the temperatures.
Unless I've missed something I think you'd be wasting your time.
 
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