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fishbmw

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I have been hearing rumbles about the F-series stators going out around 20,000-30,000 miles. I just picked up a 650 this summer and plan on putting a lot of miles on, and don't want to have to worry about this on a trip. Anyone else hearing about this?
 
My F650GS twin stator went out at 39K miles. BMW won't sell just a stator it comes as a kit with a stator and flywheel for the ridiculous price of $900. This kit now comes with an updated flywheel that has holes in it thats supposed to help keep the stator cool. Who knows if it works.

I wasn't interested in dropping nearly a grand for a simple stator so I bought an aftermarket one from Ricks for $165. You pull the sidecover off and the stator is bolted to the inside of the sidecover. I had to cut off the plug on the end of the stock stator and solder it onto the new stator. Then bolt the stator back onto the sidecover, install the sidecover and I was good to go. Why the kit doesn't just come with a new plug I don't know. Since I bought mine there is another company making stators for the 800's now so maybe its a direct replacement without having to solder anything.

For the price of the Ricks I can replace the stator 5 times with change left over compared to the price of the BMW one.

The F800 Riders Forum has a thread that will tell you more than you want to know about the stators on these bikes.
 
Voni's F800S stator too failed at about 60K miles. I replaced it with one from Rick's. I'm not positive but I believe the windings on the one from Rick's are more robust. I really don't expect another failure.
 
I was wondering if the Rick's you are all talking about is Rick's in New Hampshire? OM
 
I've been active on this problem over on ADVRider... so here's a 50,000 foot fly-over:

The original design flywheel is just a solid "cup" so there is no air cooling to speak of,
there is no (injected) oil cooling, and the way the stock Regulator works on this bike (shunt style),
it is always demanding maximum output from the stator ... so.......
The old design stator gets quite hot (~200C or higher) and in at least some cases the insulation on the windings is compromised.

The new "ventilated" flywheel from BMW is supposed to help ... albeit at a huge cost.

I'm not sure if the stator included with the $900 BMW kit is an upgraded design over the original or not....

Starting at some point in 2011/2012 the regulator was changed slightly to provide a better/higher voltage to the battery;
it is still the shunt style that runs the stator "flat out all the time" but the higher voltage helps the stator a bit, and the battery likes it better as well.

The Rick we are talking about is this guy: http://ricksmotorsportelectrics.com/

This company has also started making a unit: http://www.electrosport.com

I fed Electrosport the details on the failure mode the bikes have been experiencing and they encorporated some things into the design that the feel will help the situation. They assert they modified the windings to provide a cooler running design
and are using wire with an insulation rating of 220C.

I think Rick charges $165 and the Electosport unit is $199

It is possible to rewind the stock unit as well ... not sure what the result of that would be...
"Custom Rewind" has been mentioned as a good shop for this type work: (800) 798-7282

Just for the record: I have no affiliation with any of these outfits

It does seem funny that the F650GS & F800GS bikes seem to have more trouble with stators than the old F800S / ST bikes?
Maybe it's just my perception.....

Paul:
is the flywheel on your wife's bike just a "cup" design, or does it have some ventilation or oil cooling features?
Some bikes have a oil passage in the end of the crank that meters a bit of oil into the stator area for cooling....
I don't think any of the BMWs do that............
 
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Paul Glaves (see post #4) wrote an excellent article about F-series charging systems in the December 2011 Owners News. I recommend all F-series owners read it. If you don't have the issue handy you can get it online in another part of this web site.
 
Good info everyone. I was thinking it was Rick's Motosports, I have bought from them and have been happy. They also sponsor some of the ATV shows on Monday on the Outdoor Channel. :thumb
 

Paul:
is the flywheel on your wife's bike just a "cup" design, or does it have some ventilation or oil cooling features?
Some bikes have a oil passage in the end of the crank that meters a bit of oil into the stator area for cooling....
I don't think any of the BMWs do that............

Hers is a 2007 model - the rotor/flywheel is solid.
 
My 07 ST crapped a stator and Regulator at 34,900 miles. Replaced the stator with a Rick's unit and the Regulator with a salvage unit off of ebay. So far so good but I've only put about 7k miles on it since the replacement and mostly in cool weather but it hasn't failed yet. Knock on wood.

http://advrider.com/forums/showthread.php?t=788285
 
Thanks Paul!

Very similar if not identical in design then ...
Not sure if the failure rates are higher on the GS models or if we are just bigger whinners ... :laugh

Maybe a little of each, :) but there are many GS bikes out there running around for every one F800S out there, so we would expect to see a lot more failures of any component on GS bikes compared to S or ST bikes.
 
Maybe a little of each, :) but there are many GS bikes out there running around for every one F800S out there, so we would expect to see a lot more failures of any component on GS bikes compared to S or ST bikes.

:D
Likely you are right .... I'm a bit disappointed it took this long for BMW to come up with an improved design ...
Sure wish it was less expensive to "upgrade" :hungover
 
Thanks Paul!

Very similar if not identical in design then ...
Not sure if the failure rates are higher on the GS models or if we are just bigger whinners ... :laugh

Yes I am a whinner as mine failed at 52,000 miles on the road. It was giving me clues for some time, but I did not understand. A no start a few times, thinking bad battery. Changed battery and hit the road and it got worse and woud not keep the engine running at idle. Replaced in Oklahoma City at about $1200 plus. Two hours to remove from doner bike and two hours to install plus price of a new one, and I didn't get the new flywheel. I now have 73,000 miles and all is fine so far. I check the temp of the side cover with a inferred temp checker and it is always about 30 to 40 degrees hotter the the engine block. Engine about 190 and cover about 230
Do the aftermarket ones still put out the 400 watts?
 
Yes I am a whinner as mine failed at 52,000 miles on the road. It was giving me clues for some time, but I did not understand. A no start a few times, thinking bad battery. Changed battery and hit the road and it got worse and woud not keep the engine running at idle. Replaced in Oklahoma City at about $1200 plus. Two hours to remove from doner bike and two hours to install plus price of a new one, and I didn't get the new flywheel. I now have 73,000 miles and all is fine so far. I check the temp of the side cover with a inferred temp checker and it is always about 30 to 40 degrees hotter the the engine block. Engine about 190 and cover about 230
Do the aftermarket ones still put out the 400 watts?

I believe one solution that was being touted was reducing the output to reduce heat but I don't know if anyone went with that idea. IIRC as stated above Electrosport is trying to compensate for the heat by using better wire/insulation and they say it should be good for higher temps than the stocker would get.

Roy are you saying they charged you 1200 dollars just for a stator ?!?!
 
I believe one solution that was being touted was reducing the output to reduce heat but I don't know if anyone went with that idea. IIRC as stated above Electrosport is trying to compensate for the heat by using better wire/insulation and they say it should be good for higher temps than the stocker would get.

Roy are you saying they charged you 1200 dollars just for a stator ?!?!

No the total bill was $12xx. $200 to remove from doner Bike and $200 labor to install. The parts were $845.
 
You said you didn't get the upgraded rotor though. Sounded like they just swapped the stator from the "donor" bike over to your bike and left the rotor in place.
 
I'd like to see the revised rotor with the holes to determine if one could simply modify the old style one in the same manner. Obviously balance would be important, but with the aftermarket stator it should still be way less than the BMW kit. A competent machinist could accutately drill the rotor as long as there were no other design changes to allow for the cooling holes.
 
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