POLL: stator / alternator failure on F800S / F800ST twins please vote!

[jrwooden]

The parts break-out shows that the F800S and F800ST share the same flywheel and stator design as the F800GS and F650GS twins. The -GS bikes are experiencing an abnormally high rate of stator failures. The apparent cause of the failures is overheating. The stator runs in a very confined space with no provisions for air or oil cooling. Failures seem to start at about 35K miles.

BMW has recently released a redesigned flywheel which will likely remedy the problem.
You can read all about it here: www.advrider.com/forums/showthread.php?t=706033
Post #399 has pictures of the new and old parts ...
Unfortunately, for those of us that are out of warranty, the new "generator set" is ~$900 USD.

The purpose of this POLL thread is to see if F800S & F800ST owners are also experiencing high rates of stator failures as they put more miles on their bikes.

The POLL for the -GS twins is locate here, and you can see that from the voting so far, for bikes in the higher mileage range the failure rate is approaching 50% ....

http://www.advrider.com/forums/showthread.php?t=788285

Please cast your vote!

[Dunny]

I am Number 1.....

[jrwooden]

Good job Dunny... but I can see you are not riding enough ... get your priorities straight here man!
You should be over that 20K mark by now!

[Dunny]

I've just been out on it.

3501 miles...

[jsanford]

Thanks for posting this--I hadn't heard of it. My buddy with an '11 800GS with over 20k hasn't experienced this issue either.

[danham]

Jim,

Great info here and in ADV -- thanks! Do I get some kind of diploma or certificate suitable for framing for having read that whole thread in ADV [g]?

So far so good at 15k miles, but if/when it does cook, I hope the new flywheel means it's a one-time fix.

-dan

[Dunny]

given that you've read all the info on the other side, save us the bother, and tell us all if there's a fix...

[danham]

I want my diploma first...




OK, the new flywheel appears to be the key. It has new holes and chamfered edges that apparently blow enough breeze around in there to keep the stator happier.

-dan

[Dunny]

granted. Now spill the beans...

[danham]

The BMW OEM stator runs hot, much hotter than most comparable bike alternators, and tends to fail at or above 30k miles. It requires 200C rated wire and most other bikes use 185C, so re-wind jobs done by independent shops using 185C wire tend to go poof soon after they are installed. Futzing with other types of regulators or adding resistance to lower the output of the alternator may help, but BMW has come up with a new flywheel that supersedes the old one and apparently helps cool the stator.

Jim, is that a fair summary of all 30 pages [g]?

-dan

[jrwooden]

Dan:
Yeah I think that's it .... lots of other stuff was kicked around and all that but at the end of the day...
BMW has JUST released this new ventilated flywheel and the stator looks different, likely it is beefed up,
so the new parts have not been subjected to much field testing, but my guess is that ~$900 later it will all be good.

The failures do not seem to start until 30K+ miles

There are other possible solutions for folks that do not have $900 burning a hole in their pocket, but they are not well vetted as yet.............

[Eddy G]

I'm not sure why you say that the failure rate for the higher mileage GS bikes is approaching 50%
For 20-40, 26 good, 12 fail, or a failure rate of 31%
49-60, 9 good, 4 bad, 31%
over 60, no data. under 20, 60 good, 2 fail, 3%
is 114 bikes a statistically significant sample size? I'm not sure. Any idea on how many GS bikes were sold?
Nonetheless, an approximate 1/3 failure rate above 20K miles isn't pretty. Then again I'm almost to 60K and no failure (fingers crossed).

[Rider]

My 07 800S went 93,000 miles and no stator problem; my wife has 55,000 miles on her 09 F650GS and no problems yet; my 08 800ST has 23,000 miles on no problems yet

[jrwooden]

I'm not sure why you say that the failure rate for the higher mileage GS bikes is approaching 50%
For 20-40, 26 good, 12 fail, or a failure rate of 31%
49-60, 9 good, 4 bad, 31%
over 60, no data. under 20, 60 good, 2 fail, 3%
is 114 bikes a statistically significant sample size? I'm not sure. Any idea on how many GS bikes were sold?
Nonetheless, an approximate 1/3 failure rate above 20K miles isn't pretty. Then again I'm almost to 60K and no failure (fingers crossed).

You are indeed correct 100 or even 200 bikes isn't a statistically significant sample size.
The numbers are morphing as more votes come in....
Based on the mode of failure it would almost seem fair to discard bikes with less than about 25K or 30K miles from the sample set,
I don't think anyone is going to see a failure ... of the type we're concerned about ... with less mileage than that...
I'd like to see at least a handful of votes from the 60K+ crowd ... but I guess that's a real small "crowd".

I don't know what I was thinking in the beginning, likely the only thing this survey can do is "heighten awareness" of this potential weakness in the bike.

I don't expect any loving from BMW ....

[FredRydr]

BMW knows the stats, but they're not gonna tell.

Fred

[Paddy]

The alternator has failed on my 2010 f800st 6k on the clock. Is this a common fault or am i just unlucky (as the dealer told me today)?!

[danham]

If the stator burned out this is very unusual at 6000 miles. As for luck, well, you are under warranty and will presumably (worth checking) get the new style flywheel, which is ventilated to help prevent this. So not paying and getting the improved part is lucky, compared to those who paid out of pocket when their stators failed and did not get the new flywheel. Somewhat slim consolation, I admit, but...

-dan

[Paddy]

Thanks Dan - Yes - the bike is still under warranty and is at the dealers now. Have just emailed them to see if i'll be getting the new flywheel.

[jrwooden]

Paddy:

I would try to "insist" on the new design to whatever extent you can do so...........

You want the one on the LEFT ... not the piece of crap on the right...
http://at.fotoalbum.eu/rubbermuh/a695272/00000010

[danham]

It's not so much that the one on the right is a piece of crap -- it's a perfectly decent flywheel as far as flywheels go -- but that the piece of crap stuffed inside it (stator) needs a bunch of extra ventilation because it is a poor design, and may remain one even with the new flywheel. So fingers crossed that those fancy beveled holes will blow enough air in there to offset the weakness of the stator.

-dan

[jrwooden]

There may be another way to fix this problem... see:

http://www.advrider.com/forums/showp...&postcount=465

[Paddy]

Hi all - Here's the reply from the (rather helpful) dealer regarding alternator failure on 2010 bike 6000 miles, still under warranty.

'We are replacing your alternator which comes with a new fly wheel attached to it, we will be fitting the latest parts available from BMW'.

'

[jrwooden]

Paddy:

This is very good for you, If at all possible I would try to get a look at either the parts, or the bike before they button it back up,
just to insure that you did get the new design ...

[Lléo F]

I'm a curious is the failure could depends of climat (UK, US Texas, North-South, humidity, etc.) also if you're riding alone or with companion (2 pers. on one bike)? My voltage regulator died on 9.5K miles (~15000 km) cuz last 0.5K i was ride with my girlfriend, and after that the R/R was fried. Most of my riding is stop-ride-stop (commuting in capital of PL) - meybe this is some clue?!

BTW Hello F800riders

[Paddy]

Hi Lléo, I live and ride in London England where it hasn't stopped raining since April! Bike is kept under cover overnight though. I've never carried a passanger.

[VLT]

Any idea when BMW started shipping F800 with this new fly wheel in them.

[jrwooden]

The first time one was seen in the spare parts channel was early May 2012... so just guessing ... they probably started going into production bikes in 1st quarter 2012?

[jrwooden]

Folks:

Good news for those of us with the old design and no more warranty coverage ...
As some of you already know, I have been talking to Electrosport about the stator issues with our bikes and fed them the technical details of the issue some months back - I just got word from my contact there as to the results of the testing of their prototype replacement stator unit --- engineered to overcome the defects in the OEM unit. Here's what he says:

Testing went well and we're making a good sized (production) batch. We are hoping to have them available in a few weeks for regular sale. We changed the winding set up and a lowered internal resistance of the wire/winding which helps a lot in keeping the stator cooler.

Procom Engineering / ElectroSport
66 Maxwell, Irvine, CA 92618
PH: (949) 748-6338
www.electrosport.com
info (at) electrosport.com

I don't want to post my contact's name here on open forum but he is the guy that answers queries to the e-mail address above... or you can PM me for his name. I'm just a bit nervous about posting it publicly. For those of us out of warranty, I think this could be a very good option ... prices are not available as yet, but should be less than $150 USD.

Jim


PS: Just for the record: I have no affiliation or financial relationship with Electrosport

[Eddy G]

You can now move me to the 60+ and no failure category. (and my fingers are still crossed)

[SmithSwede]

My 2007 F800S's stator burnt out at 31,500 miles. Mostly interstate riding in Dallas. Got it re-wired by Ricks, and has worked fine for last 10,000 miles.

[jrwooden]

Several guys in my area have used Ricks ... so far so good.
I wish I knew the temperature rating of the insulation on the wire Rick uses...........

If mine blows up, I'll be getting an ElectroSport ... heck I might get one anyway !

[drrags]

It's not a complete failure as it will still charge the battery if I have no load. That means I have to disconnect the headlight though.
2009 F800GS
41,xxx miles.

[jrwooden]

It's not a complete failure as it will still charge the battery if I have no load. That means I have to disconnect the headlight though.
2009 F800GS
41,xxx miles.

draggs:
I've not tested one, but it's my opinion that the Electrosport stators should be a well designed item ...
PM me if you want the name of my contact at Electrosport.

[drrags]

I went to Electrosports webpage and, while the BMW's were in the drop-down menus, the result stated that there was no product available, so I placed an order with Rick's Motorsports. $169. I'll post the results.

[jrwooden]

Sorry if I caused confusion ... see my post #28.
Electrosport does not yet have them in stock, likely available early August.

[drrags]

I replaced the burnt out stator with a new one from Ricks Motorsport Electronics. I did not follow the directions to use the supplied leads though. I cut the leads from both stators and soldered the BMW leads to the Ricky's stator. Then I installed it, connected all the wiring and fired it up. No problem and all works like the old days. I had every device I had turned on for 60 miles and read a constant 13.8v to 14.2 at speed, down to 13.1 volts at idle. $169 well spent

[iluxa]

Got second failure
First one was after 84K kms, second (stator was rewired) occurred after 108K kms.
Rewired stator lasts for 24K kms.
Sent it for rewiring and bought Ectrosport stator for backup.

I can notice that this BMW design bug started to occur when I changed my work and started to ride about 160 kms to work instead of 50 kms
So this BMW design bug seems to be reproduced more frequently in hot Israeli weather

I know that Israeli police changed flywheels and stators to newer version in all they F800GS bikes. Before this change they rewired stators after 20-30K kms. So these batsrads are using my tax money for they bikes upgrade rrrrrrrrr
unfortunately i don't want to spend 1200$ (if I buy it in Israel - it will cost 2500$) ...

[jrwooden]

(if I buy it in Israel - it will cost 2500$) ...

We have a really LONG thread going over here:
http://www.advrider.com/forums/showthread.php?t=706033


I think the BMW redesign likely fixes the issue.
I also think original owners of earlier bikes should have received this fix @ no charge.
But ... alas, I'm sure it won't happen...........

Electrosport asserts there design at least helps address the issue, and I believe them,
but they have not been in real world testing long enough for any reliability data to have been collected.
As a suggestion ... You might want to switch to the Electrosport now and save your current one as a spare.

Other thing that is being tried is switching to a series-style R/R design that does not run the stator flat-out all the time...
I hope to have additional data on that later this weekend ...

[iluxa]

Thats what I did. I rewired my stator and ordered Electrosport stator from ebay as backup.
I will try to speak with Israeli BMW importer, however I'm pessimistic since I'm not original owner and have 109K on my odometer.

[NickW]

Don't know, got mine with nearly 40,000 on the clock. Been ok the last 6000 miles!