KTM 640 Horrible engine noise!!!!

Discussion in 'Thumpers' started by moto_psycho, Feb 9, 2013.

?

What is the horrible noise?

  1. Cam chain tensioner

  2. Camshaft rockers / bearings

  3. Big end

  4. Gearbox main shaft bearing

  5. Crankshaft bearings

  6. Other?

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  1. gunnerbuck

    gunnerbuck Island Hopper

    Joined:
    Nov 19, 2005
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    4,430
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    Yes the seals are there, but you may have to replace the shaft if it shows a wear ring on the sealing surface...
    #41
  2. ericGSsti

    ericGSsti Been here awhile

    Joined:
    Oct 9, 2009
    Oddometer:
    608
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    Dublin, Ireland
    Just to let you know my finding. The head Mechanic from KTM here in Dublin rang me to call into him today so he could show me the damage and wear that had caused my noise and metal that was found on the sump magnets. He was concerned when I had dropped it in and I had told him it had broken the teeth on the starter gear so that where he headed for first to investigate. Turns out all my noise is caused by the starter clutch assemble and fly wheel. There is a lot of wear on the starter clutch and it's relivent components. The clutch itself should only spin one direction but turned both ways and there was wear on every thing else so he's replacing the whole starter clutch assembly and I'll have it back Friday.

    Hope your finding aren't to bad.
    #42
  3. wrk2surf

    wrk2surf on the gas or brakes

    Joined:
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    Oddometer:
    7,004
    Location:
    THE exact center of California/Bass lake/Yosemite
    It will probably now need a flywheel or some machining on it to get the gouges out.. surpised the sprague would not have disintegrated
    #43
  4. ericGSsti

    ericGSsti Been here awhile

    Joined:
    Oct 9, 2009
    Oddometer:
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    Fly wheel is been replaced with a new one.
    #44
  5. moto_psycho

    moto_psycho Nob.

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    Oddometer:
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    Probably gonna ditch the starter motor on mine, so no worries if it is the cause :evil
    #45
  6. Broooce

    Broooce n00b

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    #46
  7. Rocket Scientist

    Rocket Scientist Adventurer

    Joined:
    Jul 6, 2012
    Oddometer:
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    Location:
    Brighton,CO
    My money is on a spun crank bearing.
    #47
  8. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
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    Location:
    ipswich, england
    [​IMG]
    #48
  9. moto_psycho

    moto_psycho Nob.

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    Oddometer:
    122
    Location:
    ipswich, england
    [​IMG]

    [​IMG]
    #49
  10. moto_psycho

    moto_psycho Nob.

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    Oddometer:
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    [​IMG]

    Looks like bad scoring, but you can't even feel it!
    #50
  11. Dolly Sod

    Dolly Sod Red Clay Halo

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    Do those roller bearings on the rockers have any play in them?
    #51
  12. moto_psycho

    moto_psycho Nob.

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    Oddometer:
    122
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    ipswich, england
    Sideways play in the rollers, no up/down or twist.

    [​IMG]

    Guessing the stator cover doesn't seal very well! :huh
    #52
  13. Dolly Sod

    Dolly Sod Red Clay Halo

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    Richmond, Va
    You been losing coolant?
    #53
  14. moto_psycho

    moto_psycho Nob.

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    ipswich, england
    Nah, but I will be rebuilding the pump.
    #54
  15. moto_psycho

    moto_psycho Nob.

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    Oddometer:
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    Stuck now, need flywheel puller, spanners for the base bolts, and a large flathead screwdriver for the chain guide...
    #55
  16. bmwktmbill

    bmwktmbill Traveler

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    Your cylinder looks better than mine.
    bill
    #56
  17. moto_psycho

    moto_psycho Nob.

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    Oddometer:
    122
    Location:
    ipswich, england
    If it's the same further down I won't get it plated. Maybe a new piston? If all I'm changing is the big end bearing then I may splash out on either a nice piston or the rally cam... :evil
    #57
  18. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    122
    Location:
    ipswich, england
    [​IMG]

    [​IMG]

    [​IMG]

    Looks like I got there just in time, plating measures well, and can't feel any damage. Piston is starting to wear so will replace that. Just gotta wait for my flywheel puller to turn up (****ing Sundays!!).

    Definitely what I would call 'too much play' on the big end.

    Any advice on splitting the cases?

    So, the bill so far,
    £65 - Electric Impact Wrench
    £18 - Electric Screwdriver (so fed up with twist,ratchet,twist,ratchet,twist)
    £80 - Athena Gasket Set
    £22 - Flywheel Puller

    And will be purchasing
    £136 - Pro-X Conrod Kit
    £140 - Wossner Piston Kit
    £60-80 - Crank Rebuild


    So far is £448, will be rebuilding the water pump too... sigh.
    #58
  19. achile

    achile Been here awhile

    Joined:
    Aug 14, 2007
    Oddometer:
    289
    Location:
    Brasov, Romania
    yup...all of them sound like a can of bolts rattling around. And they do a funny thing while idleing on the stand...they move! :rofl



    Moto_psycho, how are the valves?
    #59
  20. moto_psycho

    moto_psycho Nob.

    Joined:
    Nov 9, 2008
    Oddometer:
    122
    Location:
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    How do you mean? I am yet to remove, lap and change the seals, need to borrow the spring compressor off of my Dad tonight.

    How might I go about measuring the bore for piston size? Wossner have 3 sizes 0.01mm different, I know that is fuck all, but what clearance am I measuring here?
    #60