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F800GS Stator cooling system

Discussion in 'Parallel Universe' started by sblissner, Nov 8, 2019.

  1. sblissner

    sblissner Adventurer

    Joined:
    Mar 30, 2010
    Oddometer:
    91
    Location:
    Hendersonville (Nashville) Tn
    Suffice it to say my 2009 gs with 70,000 miles is now on its third stator. Number 1 failed at 30,000 miles +/-, number 2 at a little over 60,000 miles while returning from Alaska in August 2018. The records provided by the first owner, I am the second, show that the dealer in GJ Colorado replaced number 1 and charged $1100.00 plus for the BMW stator and flywheel. Problem remedied forever, right?

    The BMW parts were supposed to fix the problem, stator plus new modified flywheel. Item 1 in the diagram at $1187.00. Supposedly fixed by 2011 on all bikes from the factory but I have seen used late model stators for sale on ebay with badly discolored windings, near failure.

    [​IMG]

    As I mention above, stator and flywheel number 2 were the BMW parts, and were supposed to include the new ported flywheel to improve oil circulation to the stator. The BMW dealer in GJ Colorado did not install the flywheel so the new stator lasted 25,000 miles. I have since replaced it with an aftermarket stator from euromotoelectrics.com, while stranded in Alaska summer 2018.
    Great people to deal with, they shipped to Fairbanks from Denver on Friday and I received the parts Tuesday morning via USPS priority mail.

    To prevent future failures I also devised a cooling circuit to flood the stator with engine oil to reduce operating temps. Inside the elbow is a carb jet that I resized to limit flow and maintain engine oil pressure, which it does, but still provide adequate flow to stator to drop the operating temp of the stator, as determined by measuring the temp of the cover, from 280 degrees f to about 210, essentially the same as the oil temp after it leaves the cooler.

    So far so good, only time will tell.

    [​IMG]

    [​IMG]
    #1
    lexaria and dpike like this.
  2. headstaller

    headstaller Long timer Supporter

    Joined:
    Jul 22, 2011
    Oddometer:
    1,789
    Location:
    Norco, CA
  3. dpike

    dpike BeeKeeper Supporter

    Joined:
    Nov 21, 2015
    Oddometer:
    1,994
    Location:
    New Jersey
    pretty slick fix.
    i took the cowards route and got a vented flywheel from ebay at the first failure at around 10k miles on my '09
    #3
  4. sblissner

    sblissner Adventurer

    Joined:
    Mar 30, 2010
    Oddometer:
    91
    Location:
    Hendersonville (Nashville) Tn
    When yours fails again contact me. I have a spare cover and could do an exchange with mods.
    #4
    runnr548 likes this.
  5. runnr548

    runnr548 BMW Pilot

    Joined:
    Mar 16, 2012
    Oddometer:
    206
    Location:
    The Atomic City
    I like your Stator cooling system mod. Do you have details on your the parts you used? I am very interested. Also, do you think wrapping your exhaust helped much? Thanks!
    #5
  6. sblissner

    sblissner Adventurer

    Joined:
    Mar 30, 2010
    Oddometer:
    91
    Location:
    Hendersonville (Nashville) Tn
    2 fittings
    1 1/8 in male pipe x 1/4 inch flare 90
    1 1/8 inch male pipe x straight flare
    8 inches of tubing
    one carb jet for a Yamaha wr426.
    3TJ-1494F-10-00

    I used 1/4 " steel brake line which of course is harder to bend and flare than copper.. If I were doing another I would use 1/4" refrigeration copper.

    I removed the side cover while I drilled and tapped it to prevent metal chips in the system from blocking the jet. .In the photo you'll see that I took a carburetor jet from a WR426 Yamaha and drilled out to 1 mm. I checked and I still maintain proper oil pressure in the system. Drilled the fitting about .005" under the jet size then pressed it in and staked it in place.

    I really don't think the exhaust wrap helps much, I tried that to lower the temperature of the cover, as measured by my infrared thermometer but saw none.

    Just too lazy to remove it.


    Here is a link to all of my photos.


    https://photos.app.goo.gl/JNTB7HHgJerpFNno7
    #6
  7. cathulu

    cathulu Been here awhile

    Joined:
    Jan 4, 2010
    Oddometer:
    207
    I notice one could drill a small hole in the stator cover to spray the outside of the flywheel with oil, say a drill the same diameter as your jet. This would on the exterior surface of the flywheel and not the interior where the stator is, but it would be clean and easy. Certainly it would help lower temps behind the cover? How is your bike running with the mod? Thoughts??
    #7
  8. cathulu

    cathulu Been here awhile

    Joined:
    Jan 4, 2010
    Oddometer:
    207
    PS How easy does oil move from the behind the stator cover to the engine?
    #8