950 Adv overheating with two fans?

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Jdeks, Apr 21, 2013.

  1. Skinner

    Skinner Mr.KTM

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    It seams pretty obvious from my couch, that adding more odstruction will cause the temp to rise faster, and the second fan will help cool it back down faster. I think you answered this question yourself numerous times, but are just looking for reassurance.
    Sounds like a good trade off. I wouldn't worry about it.
    #21
  2. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    I just want reassurance! :cry Makes me feel warm and fuzzy on the inside.

    Actually, I just wanted to see what people thought, in case there was something sinister going on and I was too dumb to see it. Got a trip into a desert in the coming weeks - figured I probably want to make sure my cooling system is all tickety-boo.

    Goti, thanks for clarifying. It's sounding like your bike is behaving similarly to mine, so now I can go feel warm and fuzzy,:norton
    #22
  3. larryboy

    larryboy Chopper Rider

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    There doesn't need to be a visible leak. You can't assume the cap is good, pressure test it or replace it. Pressure test the whole system to make sure it's holding pressure, pressure is how it stays cool.

    Take the thermostat out and look at it.
    #23
  4. men8ifr

    men8ifr Been here awhile

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    If that's the thermosat (stops water flowing out the engine until about 80deg +) and not the temp switch (turns the fans on) then an open thermostat will run the engine cooler - if the bike is not flat out at low speeds the engine temp will be too low nearly all the time.

    The thermostat may not be opening properly (less flow through the rads) but doesn't sound like it really. If you need to test it drop it in boiling water and look at how far it opens.

    I run a lower temp switch with my 2x fans and works great in the desert - the switch is the same as a car type but forget which make/model at the moment.
    #24
  5. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    Okie doke, thanks. What's the procedure for pressure-testing?
    #25
  6. DustyWheels

    DustyWheels Nomadic motorcyle traveller

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    I had similar symptoms to what you've described, I replaced the cap as part of a systematic process of elimination, Problem disappeared.
    #26
  7. Pete640

    Pete640 Long timer

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    Similar problems experienced atm. Coolant leak - only very slight from the impeller cover seal. No seal lets the pressure out and coolant boil making everything else very hot. I only noticed it as there was a little weep in the void just to the front of the clutch.
    Hard to catch as it was evaporating with the heat of the motor when I stopped.
    #27
  8. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    Larry, Pete, you were right. In the worst way.

    The breather hose is full of yellow oily gunk, and I.just dumped the oil, its ever so slightly milky. Oil filter has a slight wave in some slats. So there is.indeed a coolant leak...but where??

    First instinct says pump seal, but its only about 20000km old. The seal at the base of the case breather hose is only 2000km old too, but theres evidence of milky oil coming out of the hollow balancer shaft . Someone else told me replace head gaskets!! Could they be the culprit? I would think I'd see oil outside the case for that, but I don't. However, when I did the valves 2000km ago I.re-torqued the head nuts (one by one, of.course). Could that have unsettled the gaskets and started a leak? Do I have to replace them or.just re torque the head nuts? They are the updated ones with washers

    What else could cause milky oil to come out the breather hose?
    #28
  9. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    Update: pulled the pump seal, covered in grey goop, visible coolant on the oil side of the seal. So I think (hope) its the seal, not the gaskets.
    #29
  10. Pete640

    Pete640 Long timer

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    Id be very surprised if it were the head gaskets, theyre very robust and there sould have been other symptoms. Thats easy to check with a cylinder pressure test.

    You havent said if you thoroughly flushed the coolant system when you did the seal last time. When I did mine I got about 2 table spoons of sand/grit out of it and therein lied the problem. Having said that the original seal did very well to last 30k km with that much crap circulating around.

    Re-do the seal and make sure your careful with the lip. Let us know how you get along.:deal
    #30
  11. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    Cheers pete, I agree its probably not head gaskets (maybe that's just wishful thinking on my part though).

    Coolant system was flushed by the garden hose method-is this sufficient?
    #31
  12. Pete640

    Pete640 Long timer

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    Garden hose - no problems. Works well but remember to do the overflow bottle and radiator. Depending on km's it might be worth taking the radiator to a specialist for a proper clean???

    Head jasket - much harder to fix than a waterpump seal.. Id take the WP seal anyday...
    #32
  13. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    Replacing the water reservoir entirely , and flush the whole coolant system again
    #33
  14. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    So I'm having some trouble getting a new clutch cover gasket.

    Is there any reason I can't use.gasket goo on the clutch cover ( the larger inner one) for a few thousand K's?
    #34
  15. Pete640

    Pete640 Long timer

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    No reason you couldnt but its not reusable like the O ring seal for the cover or are you talking about a different seal? Have a look here and i d it ???

    http://www.boltonmotorcycles.com/find/fiche/214472

    # 4 or 2?
    #35
  16. Pete640

    Pete640 Long timer

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    Im reviving this thread to add some info..
    I replaced all of the hoses with Samco silicon hoses (orange of course) and used the crimp clamps figuring I wont be changing/moving any of them that are in hard to get at areas of the motor which is basically all of them. The 2 that run from the radiator I reused the spring styled clamps, you know the ones you open with pliers, as they were working before so why not now???
    As a few have detailed here I also had an issue with the temp creaping up in traffic (2nd fan/thermo switch installed) or other slow going. Along the way Id noticed a minute coolant weap from the WP housing so a new seal fixed that pronto but this lead to another little leak past the return hose to the radiator past (you guessed it) the spring styled clamp!!!
    All of my previous (KTM) bikes have had screw styled clamps on these hoses so why not the 950? The rad cap does its pressure thing when necessary so my thinking is that the small leak past these clamps is enough to de-pressureize the system and thus let the temps increase accordingly.
    So off to enzed (automotive hose supplier) I go and armed with 2 new quality hose clamps I replace the 2 on the radiator and guess what? The temps have become way more stable than before. Hovers on 3 - 4 bars in traffic and takes longer to reach this temp. I havent had a chance to have a long ride through the twisties off road but its already made a huge improvement over my previous situation.
    If your having this problem then for the small investment it might be worth trying this mod before you delve into the deepest reaches of KTMs finest motor to date!
    Fin
    #36
  17. Jdeks

    Jdeks Accepting and supportive of everyones feelings.

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    Hey Pete, thanks for the update.

    I ended up doing about 3000km out to the SImpson and back with the system as is (twin fan, standard thermo switch), and a replaced water pump seal, and breather/balance shaft seal

    Temps were same deal as always - jumps up to 5 bars in moderate work .... but never any higher. Putting around caravan parks in first for 15 minutes looking for a spot - 5 bars. 60kph on twin track - 5 bars. Redlining it going up dune after dune in 30 deg heat - 5 bars. Got it to 6 brs once for a glimmer after some real heavy trench digging. So I think it holds pressure fine - it's just obstructed airflow. Expansion bottle levels rose and fell a cm or so with the heat as you'd expect, but no major overflows, so thinking head gaskets are OK. Oil filter not wavey, oil dark but not milky. so I don;t think I've got any blown seals.

    The milky oil from the breather hose turned out to be a mix of carb icing and operator error. In my haste I overfilled the oil, which causes it to typicall vent from the breather hose. Cold humid conditions between VIC/ACT were perfect for carb icing, which bought in a whole bunch of moisture, which left via the breather hose mixing with the oil. As soon as I siphoned off the excess oil and went to warmer country, it completely cleared up. I haven't had a repeat now I'm back here....yet. So I think that was the cause.

    But there is one thing - the coolant(Motul MoCool) changed color. Not turned milky, but went from clear purple to clear green. Maybe it was the heat and the fact I used tapwater? :huh
    #37