Burnt Stator problem SOLVED!!!!

4 words- Shindegen Sh847 regulator rectifier.

This series regulator is one hell of a beast. Keeps my stator mighty cool, about 100-180 degrees cooler because it just tops off the battery instead of demanding all 400w all the time like the stock shindegen shunt stator.

Love it- hopefully this stator will last as long as the bike does.

My volt meter shows a steady mid 14v range

Do this before your stock stator goes because aftermarket ones have less heat resistant coils like the electro sport models.

"about 100-180 degrees cooler"

How did you determine that?

Temp gun

Directly on the stator or the regulator? It's pretty difficult to get a reading on the stator on a bike that is running and being ridden. You would need to have an internal temp sensor directly on the coils of the stator.

Any reading taken on the regulator wouldn't count. The OP was referring to the stator. A temperature gun would not take the temperature of the stator. Temperatures taken of the cover have far too many variables to be relied upon as indicative of stator temperature.

Also "Just tops off the battery" is not meaningful in the discussion. We are concerned with what heat is generated in the stator here. The vast majority of operation will take place with the battery re-charged following the discharge that results from running the starter motor. Does the current dumped by the shunting action of a shunt regulator contribute significantly to stator heating? Certainly it contributes something but I have yet to see any data supporting a number. A shunt regulator does not demand 400W all the time.This is a myth perpetuated by internet posts.

See this thread, posts 6, 9, 11, 22 and 41.
http://advrider.com/index.php?threads/wondering-about-the-stator-problem.1181066/

That is what I am saying or at least alluding to.
Unless there is an internal temperature probe taking readings directly from the stator windings the data is flawed.
Readings at the regulator mean nothing. Actually, if the stator is running cooler and the regulator is responsible for that the regulator should run hotter trying to dump excess power unless there is another device dumping the excess.

"if the stator is running cooler and the regulator is responsible for that the regulator should run hotter trying to dump excess power unless there is another device dumping the excess"

Well there is no "excess" power. The power generated is a function of the voltage generated (in turn a function of the strength of the magnetic field and the speed of rotation), the current drawn and the phase relationship between the voltage and the current.

The power dissipated will be equal to the power generated with the dissipation being in the form of miscellaneous internal losses in the stator, losses in the regulator/rectifier and power consumed by the aggregate load.

The rectifier/regulator will have to dissipate heat resulting from the current flowing through the forward resistance of its rectifying diodes and whatever active component is acting as the regulator - whether it be a component in series with the load or a component shunting the load.

The PMA is NOT putting out a constant power.

If anything a series regulator is more likely to run cooler than a shunt regulator simply because it passes less current.

How many KM/Miles on Shindegen Sh847 I have 115000 KM on stock stator/rectifier not left me on side of road yet. Well could be famous last words but a " temp gun " in garage
for me is like arm chair quarter back.

I think the stator problem is pre '13 models. After '13 and should be fairly reliable.

Is that correct?

correct.

I just picked up a "vented" flywheel from ebay for my 2009 F800GS. Isn't the vented flywheel a better fix than just upgrading the voltage regulator?

Well, to be honest If you go to the stator thread on here you will see people with 2013+ with burnt stators. It sure will help but I believe the sh847 regulator will fix it even with the old flywheel


Sent from my iPhone using Tapatalk

As an instructive explanation of the benefit newer style regulators provide I would point the reader to the schematics on the linked page below. Simply note the lines marked "control" on the schematic. Most R/R's don't come with this. They instead use a load resistor to "shunt" excess power not consumed. Unfortunately this also means full current in the stator at all times. So it's quite likely there is something to this. Obviously being able to turn it on and off when needed is beneficial. IIRC somewhere on this forum is a before and after photo, taken with a FLIR or similar thermal imager, that shows quite a difference in temperature. Certainly there is value in using a heat gun for a basic measurement; it's just not super accurate data. Such a test would have a controlled environment, bike on a dynamometer, NIST calibrated thermal imager, etc, etc.. Beyond the scope of "just a hobby". IMHO the temp gun is good enough for me. This is on my list of mods for my bike but I'm not in a rush as I think demand will grow, thereby decreasing production costs, and amperage will increase. Perhaps a full wave, three phase, MOSFET with full control. We shall see.

Link: http://www.shindengen.co.jp/product_e/electro/catalog.html

PS: Why they even bother to build full shunt style RR's is totally beyond me. 100 year old tech not even used on cars and they stick them all over bikes. Stupid.

All shunt type regulators have a control function as represented by the simple box in the linked connecting diagrams. There is no shunt resistor in a shunt regulator. The shunting is a near short circuit. The shunts are turned on and off as needed to regulate the output voltage. The shunt regulator does not shunt power, it shunts current. A true test would need to be done outside the engine with a variable speed motor to spin the magnets, a variable load and a temperature probe embedded in the stator. Regulation by series regulator and shunt regulation could then be compared under constant and controlled conditions.

Would someone claiming that there are 2013+ bikes with failed stators in the alternator thread please point one out?

http://advrider.com/index.php?threa...re-on-f800gs-f650gs-twins-please-vote.788285/


Sent from my iPhone using Tapatalk

Klrhani did you miss this, two post since it was asked, no answer. I'm interested too.

And this V

I went on control rides popped the flywheel cover off then popped the stator off, waited 30 seconds to dissipate the ambient heat. And shot it with the temp gun- the series style had a lower temp when the ambient heat dissipated.


Sent from my iPhone using Tapatalk

You might need read through and post on the Poll thread to get to those people


Sent from my iPhone using Tapatalk

I have followed the stator discussions closely since 2010. I don't recall ever seeing a report of the new flywheel design failing. I could be wrong. Some claim it's happened. But where?

Sent from my SGH-I747M using Tapatalk