lower conrod & main bearing failure on KTM 640 ADV -03?

Discussion in 'Thumpers' started by RobinW, Mar 3, 2008.

  1. RobinW

    RobinW n00b

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    What would make the lower conrod and main bearings have a failure in less than 15000km of highway use?
    Bike is serviced according to specs and even had an extra oilchange and the auto decompressor fixed at 7500 km.

    The -03 already had the upgraded roller bearings, so what happened?
    #1
  2. humdinger

    humdinger bp

    Joined:
    Feb 13, 2006
    Oddometer:
    616
    Location:
    South eastern coast , Australia
    1/ Revving the bejesus out of it in freezing temperatures before the engine reaches its optimum heat range.
    2/ Got a lemon
    3/ Viscosity of oil incompatible with climate temperature.
    4/ Someone working on the bike fucked up big time
    #2
  3. NICO

    NICO Save the USA

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    5/ There is a rubber seal on the inside of the clutch cover for the crank end . If this dries up or is defective, you lose oil pressure and your lower end will suffer immensely.

    The upgraded roller bearing you mention for '03-later has nothing to do with the crankshaft. That is a transmission main shaft bearing.

    Sorry to hear about the problems. There is a ton of help on this board.

    Good luck.
    #3
  4. gybeman

    gybeman Been here awhile

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    Seeing as in 2003 onwards, your model also has an extra oil line lubing the same area, so something is definately wrong. Keep us posted.
    #4
  5. NICO

    NICO Save the USA

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    I thought the extra oil line was to squirt the bottom of the piston?
    #5
  6. gybeman

    gybeman Been here awhile

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    Whatever, its still extra oil in the failed area that the earlier models didn't have.
    #6
  7. gunnerbuck

    gunnerbuck Island Hopper

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    03 didn't get the extra oil line. I think it was in 04 or 05 that this benifit copied from the Rally bikes was put in.....

    My thinking is that KTM reconized the need for more oil to the piston con-rod area to help prevent what happened to your 03 engine.....

    I suffered a top end failure on my 03 as to where a chunk {probably piston ring debris} dropped into the clutch side crankshaft bearing and damaged it as well....

    Possibilities for your failure..
    Debris into the bearings

    Or like others have said lack of lubrication due to a failed end seal, plugged oil line or oil pump failure.....
    #7
  8. gybeman

    gybeman Been here awhile

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    If you have a 2003 or newer Hi-Flow head, you have the additional line line as well. See the banjo bolt and oil line on the front of the engine ?
    #8
  9. gunnerbuck

    gunnerbuck Island Hopper

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    I have an 03 with the High Flo head and it does not have this oil line.

    However I can see the undrilled bung in the casting on my engine where they put it in on the later models and the Rally engines.

    The engine in your picture also shows it with the SAS crap on the header which I believe also came in after 03 in some regions.....
    #9
  10. gybeman

    gybeman Been here awhile

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    I stand corrected. I have a 2003 brochure and it shows it without the oil line. Seeing as it lived nicely without it for years its odd it needs it now with just 1 or 2 more hp from the hi-flo head. Don't know if the piston is that radically different from 2002-2003/2004.
    #10
  11. positionsize

    positionsize Been here awhile

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    I have a High Flo 2004 Adventure and it does not have this oil line on the front of the motor. Bung only.

    They must have introduced this line in 05'.
    #11
  12. electrician

    electrician kselectrician

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    If there is an air gap in the frame with oil, it will starve the crank bearing. This comes from an improper oil change, or if the bike sits for about 9 months the oil will sump down into crank case. Make sure you have banjo bolt #150 on the oil line from frame to engine. It is restricted to prevent sumping.
    #12