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Please vote below - selecting mileage on your bike & failure(s)

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

26K views 51 replies 19 participants last post by  gladiators280 
#1 ·
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% .... [B)]

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

Please cast your vote!
 
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#28 ·
Replacement stator by Electrosport will hit the street soon

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
 
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#31 ·
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 !
 
#33 ·
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.
 
#35 ·
Sorry if I caused confusion ... see my post #28.
Electrosport does not yet have them in stock, likely available early August.
 
#36 ·
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 :)


 
#37 ·
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$) ...
 
#38 ·
(if I buy it in Israel - it will cost 2500$) ...
[xx(]

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 ...
 
#39 ·
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.
 
#43 ·
Failed at just over 20,000 miles. Replacing with Electrosport. Bought it from a third party vendor. They sent an ESG070 not the vehicle specific ESG831. Sort of a universal replacement. Anyone have any experience with this model?
 
#44 ·
It's just my opinion, but I would not use it .... per my direct conversations with the Sales Manger @ Electrosport:

The ESG831 uses a better grade wire for less heating, a modified winding pattern, and wire insulation with higher temperature rating.
 
#45 ·
I posed the following to Electrosport via email:

"Hello, I ordered a stator for the above referenced bike from ------------. An ESG070 arrived. Your site lists ESG831. Regarding the ESG070: 1. will it fit? 2. Will this hold up to the temperatures of my bike. Should I send it back? Thank you"

Electrosport replied:

"ESG070 would certainly not work on your application. I dont think it will fit, and should it fit it, would not last long at the BMW's temperature range. You will want to return this one for an exchange."

Needless to say five minutes later I ordered the ESG831 with 2 day shipping! I'll deal with the return later.
 
#46 ·
I was in the middle of a 3000 mile trip last week on my 08' F800ST when it wouldn't start one morning. The voltage was low on the battery, but an auto parts store said that it would hold a charge. I put it back in and jump started it, then tested the voltage as it was running (I bought a meter at the parts store). It was a slow drop from just over 12 volts, so it was obviously not charging. My battery was already 3.5 years old, so I bought a new one to be sure that I could ride the 60 miles to the nearest BMW shop. They looked it over and quickly decided it was the alternator. The mechanic and service manager were shocked that it died with so few miles on the bike (17,000), but said it probably had to do with me recently riding long distance (I did 800 miles the day before this happened) after it sat for years (I just bought it a couple months ago and previous owner didn't ride it much). The service manager there has an 07' F800S that he's put 105,000 miles on and has not had an alternator problem. This happened on a Saturday and of course they had to order parts and are not open on Sundays or Mondays. So Tuesday noontime they got it fixed up and sent me on my way. $1300 repair ($960 for the parts which they claimed only came in a complete kit). It made for an expensive unplanned 3 days stop in the middle of my trip...
 
#47 · (Edited)
It is true that from BMW the stator is only available with a new flywheel, and unless you got old stock, the flywheel has been redesigned and is now ventilated so that you should (hopefully) not have the problem again.

I call bullsh*t on the "it blew up because you road it 800 miles in one day after long nap" explanation...

The OEM Regulator on the bikes runs the stator at maximum output all of the time,
no matter what the actual demand for power is from the bike...
so I have trouble figuring out how your 800 mile trip is related, but then I'm not the sharpest tool in the shed.
 
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