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Thread: 87 K75S radiator fan

  1. #1
    Registered User
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    87 K75S radiator fan

    The Winter maintenance on my K75S has been like any project I've done on my home; starting a single simple job grows into multiple jobs of increasing difficulty and cost.
    Among other things, I found the cooling fan didn't spin freely any more so I removed and disassembled it. After cleaning the shaft and applying generous amounts of oil to the bearings the motor spins freely again. The question is, have any of you revived a fan motor and continued to use it successfully?
    I also wonder if there is a better alternative to the stock cooling fan and motor? There are some small fans used for car radiators that look as if they might work, another thought was to use a fan from an electronic device; has anyone done anything like any of these?
    lostandwandering
    87 K75S

  2. #2
    Registered User argent brick's Avatar
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    Quote Originally Posted by lostandwandering View Post
    The Winter maintenance on my K75S has been like any project I've done on my home; starting a single simple job grows into multiple jobs of increasing difficulty and cost.
    Among other things, I found the cooling fan didn't spin freely any more so I removed and disassembled it. After cleaning the shaft and applying generous amounts of oil to the bearings the motor spins freely again. The question is, have any of you revived a fan motor and continued to use it successfully?
    I also wonder if there is a better alternative to the stock cooling fan and motor? There are some small fans used for car radiators that look as if they might work, another thought was to use a fan from an electronic device; has anyone done anything like any of these?
    It is my understanding that motor is manufactured by Bosch and can be purchased for much much less that through BMW. Unfortunately, I can not tell you what the part number is.

    Wait for a little while, I am sure someone with more knowledge that myself will post more information.
    Lynn
    MOA #57883
    Current Ride: 1995 K75 Standard
    Past: 1978 Yamaha XS 750, 1976 BMW R60/6

  3. #3
    3 Red Bricks
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    If the brush holders haven't melted yet (from trying to run with the shaft seized) it's probably OK. Put 12v to it and see how it runs. Maybe you caught it in time.

    If not:

    http://www.beemerboneyard.com/kfanmtr0427.html

    http://www.euromotoelectrics.com/BMW.../fan-k427m.htm


    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

    Lee Fulton Forum Moderator
    3 Marakesh Red K75Ss
    Mine, Hers, Spare

  4. #4
    Registered User
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    I did exactly as you did "lubed the bearings" and it has been running for a year. It is on a k100/eml sidecar rig so it runs more often then your k75.
    Harold In Kansas
    1985 K100RT Bullit
    1985 K100XX/EML Bemel

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