KTM LC4 Crank bearings?

Discussion in 'Thumpers' started by moto_psycho, Jan 31, 2013.

  1. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    Hi guys, my bike is making a sound identical to this video, http://www.youtube.com/watch?v=uJulJeJarhE

    In which the author replied it was both his main bearings. My bike is a 2004 640, which means it should have the needle roller bearings (am I right?), would it be easier to change both bearings without splitting the cases? Or should I split the cases?
    #1
  2. It'sNotTheBike

    It'sNotTheBike Banned

    Joined:
    Jul 20, 2011
    Oddometer:
    704
    Best not to run the engine any more because if the bearings fail the crank
    and cases can be damaged severely.

    You may still find the cases have been damaged such that they cannot be re-used,
    but the best course is to quit riding it or running the engine if you hope to salvage most
    of the engine for re-use.


    .
    #2
  3. gunnerbuck

    gunnerbuck Island Hopper

    Joined:
    Nov 19, 2005
    Oddometer:
    5,570
    Location:
    N.V.I, B.C.
    In that video he stated that it was one of the crankshaft end bearings that was causing the noise...

    To replace that bearing the motor needs to be removed and the cases split, there is no other way...

    Are you certain that the noise from your engine is indeed coming from the bottom end?
    #3
  4. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    As mentioned it is exactly the same as that video. I've checked with other videos that have the rocker fault and its not the same. Trouble is I have to ride it once more next month as I am moving house. Let's hope its not too mangled in there :cry paid £2200 for this bike not long ago and another £350 for a set of wheels.

    The noise is definitely louder on the bottom end... waa.
    #4
  5. 640 Armageddon

    640 Armageddon Xplorer

    Joined:
    Mar 4, 2009
    Oddometer:
    3,789
    Location:
    Greece
    Please for the love of God do not run the engine any more... You can destry it completely as some of us I have found :cry

    If it makes a noise, start stripping the engine, top to bottom and inspect. It is better to fix something before it falls apart and it goes all over the place. You should have the new bearings but that does not mean anything. Things can still fail. How many kms/miles on the clocks ? :ear
    #5
  6. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    Literally it will be moving 3 miles to my new house, then I will start the rebuild. The bike is on 12,000 miles. Very annoying indeed.

    When the mains go do you tend to get a lit of end float? Any other symptoms?
    #6
  7. juames

    juames Have Fun, Don't Die!

    Joined:
    Aug 16, 2008
    Oddometer:
    2,864
    Location:
    Ottawa

    I was able to upgrade mine without splitting the case, was a pita but worked.

    Used this method:
    http://www.advrider.com/forums/showthread.php?t=73558
    #7
  8. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    You used the same method to remove the main gearbox bearing to do the 2 crankshaft bearings?
    #8
  9. juames

    juames Have Fun, Don't Die!

    Joined:
    Aug 16, 2008
    Oddometer:
    2,864
    Location:
    Ottawa

    Uh no...I have a 2002 that required the main bearing upgrade. But I think you're jumping the gun a little bit based on listening to a YouTube video. Do a little investigating first, take the side covers off, check the cam bearing, etc...before you think the worse case. These motors make a racket even when everything is fine.
    #9
  10. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    I'm a 'pessimo-optimist', I believe I created that term myself, basically;

    Expect the worst, and only good things can happen to you :hmmmmm.

    I will start investigating in 26 days (day after the move). I'll try to be one of those people that video's and takes photo's of everything for the benefit of everyone else.

    Suppose I'll get the frame powdercoated orange while I'm at it... standard black 640 looks a little... un-KTM like ;).
    #10
  11. gunnerbuck

    gunnerbuck Island Hopper

    Joined:
    Nov 19, 2005
    Oddometer:
    5,570
    Location:
    N.V.I, B.C.

    The main crank end bearings are pressed in from the crank side and can not be passed through the cases like the main shaft bearing you are referring to...
    #11
  12. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    I've had a good search, are there any OEM alternatives for the crank bearings? The wait has become too much and I'm going to at least diagnose this weekend!
    #12
  13. clintnz

    clintnz Trans-Global Chook Chaser

    Joined:
    May 17, 2004
    Oddometer:
    4,132
    Location:
    Rotoiti, North Is, New Zealand
    Not sure there are any other options for mains. The press-on inner race is a bit of a special item.

    Has the bike been run out of oil or something? If it is a main bearing at 12K miles chances are something else is wrong, mine were still mint at 60K miles. Be aware you need special tools to change these bearings.

    Cheers
    Clint
    #13
  14. gunnerbuck

    gunnerbuck Island Hopper

    Joined:
    Nov 19, 2005
    Oddometer:
    5,570
    Location:
    N.V.I, B.C.
    Yes, you can get the crank end bearings through a bearing shop by using the bearing #s and they are usually cheaper...

    Left side # nj 306 c3
    Right side # nj 207 ecp c3
    #14
  15. laramie LC4

    laramie LC4 crash test dummy!

    Joined:
    Sep 19, 2004
    Oddometer:
    2,802
    Location:
    Tucson, Az
    you can also find higher quality. if the person at the counter knows their job, they should be able to take those numbers and find every make of bearing available at that exact size and dimensions. chose the highest quality available that you can afford.

    laramie :beer
    #15
  16. mountaincadre

    mountaincadre Been here awhile

    Joined:
    Jul 18, 2012
    Oddometer:
    618
    Location:
    Mid Calder,Scotland
    Sorry to hear about the bike, if it is what you suspect then i would advise you to LISTEN to what these guys are telling you as they know what there on about, if you have to push the fecker the 3 miles then push it,(sweat costs nowt,a new engine will cost you 2 grand), I know it's not want you want to hear but neither is a grenading engine.
    #16
  17. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    123
    Location:
    ipswich, england
    http://advrider.com/forums/showthread.php?p=20688517#post20688517

    Refer to that thread now, so far no end float in either side of crank, clutch seems fine. Counter balance outer case bearing is fine, but without removing there seems to be a lot of play on the inner bearing. Waiting for tools to arrive to remove. I have a sneaking suspicion it is the counter balance and the cam rockers.
    #17