640 Adv DUAL radiator fans guide

Discussion in 'Thumpers' started by CountPacMan, Apr 6, 2005.

  1. CountPacMan

    CountPacMan Been here awhile

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    Most of us have had overheating problems, usually on really hot days while stuck in traffic. I've run through everything - there's no air in my water lines, I'm using a good mix, etc... there's a reason why the 660 Rally's have dual fans and today I finally picked up a second fan for my 2000 Adventure. Upon first inspection, I notice that it is the NEW fan - the one included on the new LC4s, which is MUCH bigger and it has a big casing to go with it. After I took the tank off and fiddled with it a bit, I noticed that it would take a little casing modification with the knife to get it to fit on the right side radiator because of the decompression cable, but it would easily fit on the left side where the original, smaller fan sits. Now before getting started, I recommend disconnecting the battery, or at least removing the main electrical system fuse next to the battery - this is especially important when handling the Capacitor as if you're not careful, you can short the leads on that thing and... and... well, not much, you'll probably just blow out the main fuse that you should have removed. I first removed the Capacitor and bracket, becasue it was in the way on the right side and the I removed the original fan and remounted it to the right side and put the new one on the left side. No problems so far.

    New BIG fan on the left side:

    [​IMG]

    Now I have this orange colored capacitor dangling there I can't for the life of me figure out where to put it so it doesn't make contact with something else. My solution was to mount it using the front most bolt on the Thremostat. Of course, since I'm certified, I removed the bolt and instantly had coolant shooting all over me. Do the opperation quickly and use a finger to stop the coolant while fumbling to thread the bolt in the Capacitor's bracket. The bracket can face inward (to the engine) or outward (like KTM puts it at the factory). I had to make it face inward to clear the tank.

    Capacitor attached to the Thermostat(note the coolant that shot all over the place):

    [​IMG]

    Now, it looks really nice, but there's only one plug for the fan, and now I have two of them. Easiest solution was to chop the plug off one of the fans (I chopped the old, small version as it has really thin wires) and splice them into the the other fan's wires, just before the plug. I think you gotta get the pos/neg right, but am not sure if it matters. I'm not an electrician. I turned on the ignition on and tested the setup by shorting the thermoswitch in the right side radiator with my screwdriver. Both fans instantly shot to life.

    Both fans. Looks cool eh?:

    [​IMG]

    I put everything back together and went to roast in some Bucharest traffic. No overheating, fans come on, and whats really nice, is how quickly they turn off. Normally if you sit in traffic and crawl for 15 minutes to your destination, and leave the ignition on after parking the bike, you can hear that poor little fan go for 3 minutes or more. Not anymore. The dual fans cool things down really quickly, and I haven't seen them go for more than 10 - 20 sec. after shutting off the engine.

    I had kind of hoped that having two fans would eliminate the "blowdryer" sound I get when the fan kicks on. No suck luck. Its now "Blowdryer 2: in Stereo!"
    #1
  2. meat popsicle

    meat popsicle Ignostic

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    Nice write up PacMan! Thanks for the help. How much did the parts cost ya?
    #2
  3. craigincali

    craigincali Just hanging around

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    I was just in the garage looking at a solution to this and I came up with the same idea except I am gonnna use a old fan...the small one. I will then have two small fans.

    Tell me again how to test the fans to make sure they work? You short the thermostate? How...?
    Craig
    #3
  4. craigincali

    craigincali Just hanging around

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    I was just in the garage looking at a solution to this and I came up with the same idea except I am gonnna use a old fan...the small one. I will then have two small fans.

    Tell me again how to test the fans to make sure they work? You short the thermostate? How...?
    Craig
    #4
  5. CountPacMan

    CountPacMan Been here awhile

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    Hi Craig, I'm sure it will work just as well using two small ones. Found one off a donor bike?

    Not the thermostat, the thermostat is just a valve that opens at a specific temp to let the water flow. You short the the thermoswitch, which is the electrical thingy that is screwed into the right side radiator at the very bottom. This thing just completes a circuit when the water temp rises above 85 Celcius and breaks it when it drops below 80. You'll see wires coming out of it. The wires lead to the fan. Just pull the sheath off(which hardly stays on to begin with), and you'll see two bare wires. Complete the circuit using someting metal - like a screwdriver (while holding on to the plastic handle of course) while the ignition is on(engine does NOT need not be running).

    Glad you liked it. I bought the fan from some guy here who has a 2003 Adventure and has lost his mind. He is attempting to make some sort of ultra-light rallyraid machine out of it. He's selling the fairing, fuel tank, and stock pipe as well. I have NO clue, why he thinks the fan weighs so much, but I was happy to buy it off him for 50 Euro. Thats like $68, which is close to how much it would probably cost brand new back in the States, but not here. Everything is more expensive in Euorope. Yes folks, KTM parts actually cost more in Austria in Mattinghofen than anywhere in the States, not to mention the ridiculous price of the bike itself.

    If you want to order it new, the part numbers are:

    58435041000 x 1 (fan)
    58435044000 x 1 (casing)
    58435044050 x 2 (not so important rubber flaps)
    0017060203 x 2 (attachment screws)
    0081500181 x 4 (casing attach screws)
    58312085100 x 1 (really unimportant edge guard that you could make yourself)

    I think it was under $90 for everything. I say WAS, since I did order it a while back, my brother got them in the mail very rapidly from Munn Racing in Texas, and then mailed them to me in Romania. In January. Lo and Behold, they're still not here. Surprise... :nah
    #5
  6. Frank Warner

    Frank Warner Traveller

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    How reliable are the fans?

    The ones on BNMW K series have a habit of sezing (lack of use leading to corrosion on the front bearing) and then when needed they over heat the brush area (made of plastic) that then deforms and eventaully blows the fuse ... mean while the engine is overheating ...
    #6
  7. CountPacMan

    CountPacMan Been here awhile

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    I've never seen or heard of one go out
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  8. craigincali

    craigincali Just hanging around

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    Actually, by replacing the small fan with just the large fan alone may be all it needs to stay cool..... :ear
    #8
  9. CountPacMan

    CountPacMan Been here awhile

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    not really, I've heard that the new bikes still have the problem, though not as often. Besides, they don't really weigh all that much, so if you're ordering another fan, might as well use both. There's absolutly no drawback, as you can't "overcool" it. Fans switch off when water temp reaches 80 C.
    #9
  10. rob_erto

    rob_erto Been here awhile

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    Very good post! :thumb

    had already thought of doing something similar to my transalp. As my main transportation for the city, it heats up quiet quickly in heavy traffic.
    #10
  11. meat popsicle

    meat popsicle Ignostic

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    I am surprised the shroud or cowling for the fan doesn't cover more of the radiator on that side? I guess its for air flow with the fan off.

    Parts fiche from CycleHutt

    [​IMG]

    #40
    Item #: 58435041000
    FAN CPL. 12V LC4 2000
    Quanity On Diagram: 1
    Cost Each: $83.18

    #41
    Item #: 58435044000
    FAN CAP LC4 2000
    Quanity On Diagram: 1
    Cost Each: $4.49

    #42
    Item #: 58312085100
    EDGE PROTECTOR PER METER
    Quanity On Diagram: 0,22
    Cost Each: $7.33

    #43? :dunno

    #44
    Item #: 58435044050
    FAN FLAP RUBBER LC4 2000
    Quanity On Diagram: 2
    Cost Each: $3.38

    #45
    Item #: 0081500181
    SCREW FOR PLASTIC D=5X18
    Quanity On Diagram: 4
    Cost Each: $0.78

    #46
    Item #: 0017060203
    EJOT PT SCREW K60X20 WS=6
    Quanity On Diagram: 2
    Cost Each: $1.05

    Total for a setup: $100.21 plus tax (free ship?) and some wiring work during the install.

    not bad for what you get!
    #11
  12. CountPacMan

    CountPacMan Been here awhile

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    Order through KTM Talk as a member, and you get 15% off + unless you live in the dealer's state, no sales-tax. Probably why I remember paying under $90 for the stuff originaly...
    #12
  13. techieguy

    techieguy Lost in the woods

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    You can also order the stuff from Budd at Matto Cycle, www.mattocycle.com and get the 15% discount too.

    Just click on the "KTM Parts Online" graphic and you get the parts diagram.
    #13
  14. Buckster

    Buckster Banned

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    If the dual fans run that little, it probably means that they are drawing less juice than running the single fan for much longer periods so this could be a good "battery saver" mod as well.
    #14
  15. rapiti

    rapiti IOR Veteran

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    Thank you for taking the time to write this up! I had been planning this mod, and I will likely do it after exposing my waterless coolant to Texas Summer heat. The bike does seem to run cooler, but dueling fans offer some redundancy comfort. :thumb
    #15
  16. Drif10

    Drif10 Accredited Jackass

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    I felt that the problem was not the fan, but that it kicked in so late. Couldn't change that easily (thermoswitch is non adjustable). So I just put a manual switch on the thing. Hit the switch when I get into the tight stuff, and it stays cool the whole time. Cost me 2 bucks for the toggle switch.

    No more heating problems.
    #16
  17. markjenn

    markjenn Long timer

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    Nice write up.

    I did the exact same mod a few months back. I even think I puzzled over where to put the condensor just like you and ended up in the same spot. I do recall fiddling with the bracket and orientation to find the right spot where it wouldn't foul the tank.

    BTW, in looking at the wiring diagram it appears to me that the condensor is basically just wired across the battery, so I expect you could put it almost anywhere on the bike. I wonder why they don't put it back in the tail with the rest of the electrics.

    - Mark
    #17
  18. meat popsicle

    meat popsicle Ignostic

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    I asked Jerome to post a pic when he gets a chance. He has a second fan and shroud on his bike. From recollection, I believe he mounted the shroud upside down and had to hack on it a bit - but that was long ago. He says it fit somehow... hope he has time somewhere to give us the info. :D
    #18
  19. Velocibiker

    Velocibiker Adventure Antagonist

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    I didn't use the shoud (for that very reason). I just fabbed up some brackets and mounted just the fan w/no shroud.

    I know one guy who simply cut-off the manual decomp support. Said he never used it anyway....

    I think I've only used my manual decomp once or twice. Nice to have, but I'm sure I could live without it.
    #19
  20. WageSlave

    WageSlave Been here awhile

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    bump
    #20