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Thread: K75 Cooling Fan?

  1. #1
    Maine Rider cayuse60's Avatar
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    Question K75 Cooling Fan?

    The contnuing tear down of the 1991 K75 I recently bought .

    It would seem this is not the OEM electric radiator fan. Can anyone out there identify it?

    The only part no. on it is 062500-5990, 12 4 J, MADE IN JAPAN.

    tia----tim
    Last edited by cayuse60; 07-20-2007 at 04:21 PM.
    Tim
    1997 K1100 LT
    " If you don't know where you are going, any road will get you there." And that is OK with me

  2. #2
    Seattle-area Rounder OfficerImpersonator's Avatar
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    I just replaced the radiator and fan on my '92 K75S. Your fan is definitely NOT stock. The OEM fan attaches to the radiator in three places - yours appears to only attach to the radiator at two places. You can see the unused mounting bracket at the bottom right of the radiator in your photo.

    I discovered (the hard way) that OEM fans occasionally "drill" into the radiator due to too much play on the fan shaft, allowing the shaft to come into contact with the radiator, causing a leak and requiring both a new fan and a new radiator.

    You should be able to find a used OEM fan out there for about $75. I see beemerboneyard.com had one for $78, but they've sold it. I'm sure others posting to this thread will provide links to other online purveyors of used parts.

    I got my new used radiator and fan from my independent wrench, who charged me $100 for the radiator and $50 for the fan, and another $150 to install the two. Perhaps your wrench has a supply of used parts he'd be willing to "part" with?
    Seattle, WA
    2012 R1200GSA
    2002 R1150RT-P
    1992 K75S sold

  3. #3
    Blocking the slow lane
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    Actually, if the bastard fan is working ok, leave it alone! There's nothing special about the BMW fan other than price and availability.
    Jon Diaz
    BMW K75/K12GT
    BMWMOA Ambassador

  4. #4
    Maine Rider cayuse60's Avatar
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    Quote Originally Posted by jdiaz View Post
    Actually, if the bastard fan is working ok, leave it alone! There's nothing special about the BMW fan other than price and availability.

    The fan (what ever it is ) is operable when fired up with 12VDC. The way it was mounted left alot to be desired...a new mountinting bracket and edgeing the shround with split 1/4 in. vacuum hose helped keep the shround from contacting the radiator cor. The orinal picture only shows the one bolt holding the whole assembly in place allowing the fan shround to vibrate against the radiator core.
    I removed the motor and fan and have fitted the pictured configuration to the clearances behind the fan motor and above the engine and no more contact between the fan shroud and the core.

    I'll let you know how this works, but still would like to know what I have for a radiator fan.

    ----tim
    Last edited by cayuse60; 07-20-2007 at 04:21 PM.
    Tim
    1997 K1100 LT
    " If you don't know where you are going, any road will get you there." And that is OK with me

  5. #5
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    Quote Originally Posted by cayuse60 View Post
    , but still would like to know what I have for a radiator fan.

    ----tim


    It's either for a 1958 Borgward Isabella TS or a 2006 Aston Martin DB9.

    Either way, it should be more than enough unless the bike is orange.


    Sorry, I couldn't resist.


    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

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

  6. #6
    Maine Rider cayuse60's Avatar
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    Quote Originally Posted by 98lee View Post
    It's either for a 1958 Borgward Isabella TS or a 2006 Aston Martin DB9.

    Either way, it should be more than enough unless the bike is orange.


    Sorry, I couldn't resist.


    Thanks...it will remain a mystery, or as has been stated in an earlier post...bastard fan
    Tim
    1997 K1100 LT
    " If you don't know where you are going, any road will get you there." And that is OK with me

  7. #7
    A bozo on the bus deilenberger's Avatar
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    It's not an Isabella one.. they were made in Yugoslavia.

    Whatever it is - it's probably BETTER than the POS BMW put in at the factory... that has a habit of seizing up and burning up.

    If you can come up with a clean mounting - I'd suggest browsing JCWhitney&Co website and see if you can figure out what it is - you'd have a marketable replacement for the horribly expensive and generally awful BMW OEM one.
    Don Eilenberger http://www.eilenberger.net
    Spring Lk Heights NJ NJ Shore BMW Riders
    '12 R1200R - I love this bike!

  8. #8
    DEANCOX
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    [QUOTE=dvandkq;199805] I see beemerboneyard.com had one for $78, but they've sold it. I'm sure others posting to this thread will provide links to other online purveyors of used parts.
    QUOTE]

    I bought that fan from BBY a couple weeks back and have it installed on my '89 K75C. It just saw me through my first IBA qaulification ride...so far so good, but I would have preferred a new one, but doubling up on the $78 (more or less) was against my religion.

    I understand the Bosch motors are/were used on early Porsche 911 airconditioning condensor fans, but I could never suss out the correct part number although there a list on another board that claims to have it...I couldn't verify it.

    I took my fan motor to a local rebuilder and he said not to bother. I am a little nervous to have a used fan on the bike, and I would certainly be willing to use a "bastard" fan from another application if I knew exactly how to spec the replacement out. I am sure I could fabricate a mounting.

    Anyway, my bike has an operational fan for the first time in the 3 years I have owned it. Whenever the cooling light came on in the past, I just began splitting lanes or pulled over and shut it down until I could move fast enough to get air flowing.

    Bottom line, there has to be a better answer than what BMW provides. It seems as if the design is very vulnerable to road grit, water, and the elements in general.

  9. #9
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    Dean,

    Check out euromotoelectrics.com.

    They have just about any Bosch part available for K and R bikes. Complete fan assemblies $120, fan motor only $69.

    They also carry fuel pumps $139 & $219. They carry starters and alternators, plus they carry all the rebuild kits ( brushes, stator kits, drives, regulators) if you feel like rebuilding your own stuff. Also complete Bosch line of plugs and coils and filters.

    The owner, John, is a fellow Beemer rider in Colorado who, through his connections in Europe from working at Lucas Electrics (go figure) and Bosch, decided there was a need to make this stuff available without the crazy markup. He has researched over 150 Bosch parts for our bikes and is a pleasure to do business with. Try giving him a call.

    I made the decision last year that I didn't want to trust 20 year old fuel pumps or fan motors on my bikes, especially now that my wife is riding one of them.

    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

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

  10. #10
    DEANCOX
    Guest
    Lee: Thanks! With an '89...I have the same concerns,,,,except my wife does not ride, so my concerns are more selfish....I just don't want to be bummed out on the side of the road.

  11. #11
    Maine Rider cayuse60's Avatar
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    Bastard radiator cooling fan appropriately installed.
    Last edited by cayuse60; 07-20-2007 at 04:21 PM.
    Tim
    1997 K1100 LT
    " If you don't know where you are going, any road will get you there." And that is OK with me

  12. #12
    jimmyenglish
    Guest

    Bastard fan

    So what is the bastard fan model #? I need one too and there's no way I'm going to pay oem prices for something that almost never gets used. Thanks!

  13. #13
    BUDDINGGEEZER
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    I have had to replace the fans in 1987 K75 & K100. The K75 I bought a Beemer Boneyard used fan and the K100 I bought a new Bosh motor and rebuilt the fan.

    If you have a good working aftermarket fan, don't mess with it. The Bosch fan motors tend to melt the plastic brush holder. This is the same motor used in early Porsche 911 air conditioner condensers. They also melted the plastic brush holder.

    Not a good design.

    Ralph Sims

  14. #14
    BUDDINGGEEZER
    Guest
    [QUOTE=deancox;200264][QUOTE=dvandkq;199805]

    I understand the Bosch motors are/were used on early Porsche 911 airconditioning condensor fans, but I could never suss out the correct part number although there a list on another board that claims to have it...I couldn't verify it.



    I called a foreign car parts store with the proper part number. They can't get it. Must be a dealer only item. I paid less than $70 for the new motor at Beemer Boneyard. The BB fan motor has spade terminals. My wires would not fit in the motor case with spades. I soldered directly.

    Ralph Sims

  15. #15
    3 Red Bricks
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    Once again: euromotoelectrics.com

    More Page
    Part Name Motor Radiator Fan - K models 1983-1995
    EME Part Number FAN-K427M
    Product Description Bosch Original Equipment New MOTOR; Fits ALL K models 1983-1995. This is the motor only. Some careful dis-assembly of the orignal radiator fan assembly required.
    Vehicle Manufacturer Name BMW K
    Vehicle Manufacturer Part # 1 74 01460 427, 51 33 1 460 427
    Manufacturer Name K
    Vehicle Model # K75, K100, K1100
    Engine Displacement 750cc, 1000cc
    Vehicle Model Start Year 1983
    Vehicle Model End Year 1995
    Application BMW K75, K100RS,RT, LT, K1100
    Assembly Name Motor for Radiator Fan Assembly
    Original Equipment Manufacturer
    Unit Manufacturer Name BOSCH
    Power Rating 12 V, 28 Watts, 4 Amp
    Technical Specification 4500 RPM nominal speed, 6 Ncm Continuous Torque, 35 Ncm Breakaway Torque. Spade terminals allow easy reconnection of original wire harness coupling.
    Retail Price $69.00
    In Stock
    Availailable
    Picture
    Drawing Picture
    LONG MAY YOUR BRICK FLY!

    Ride Safe, Ride Far, Ride Often

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

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