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

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    I'm not upset, just out of ideas that seem to be of any help...

    :http://www.advrider.com/forums/showthread.php?t=405073&page=2
  2. Dolly Sod

    Dolly Sod I want to do right, but not right now

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  3. bmwktmbill

    bmwktmbill Traveler

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    [​IMG]

    Errr...

    [​IMG]


    bill
  4. moto_psycho

    moto_psycho Nob.

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    Pretty cool, never realized that this was such a common problem...

    ... though I will take your idea and raise you a lazy point!

    At work the metallurgists / quality control guys use dye penetrant inspection (when ultrasonic is not viable), basically you spray on an ultra low viscosity dye, leave it for a minute, clean it off, then spray on a curing agent. If there are any cracks the dye will begin to weep from the crack.

    I know it is not as thorough as a high pressure test, but I have not lost any coolant since owning the bike, and I've had the fan cut in on tight trails many times, so I don't really suspect a head failure.

    Is there a typical mileage this problem occurs at? Really starting to get a distaste for KTM now, never known a bike ot have so many "common faults".
  5. moto_psycho

    moto_psycho Nob.

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    [​IMG]
    [​IMG]

    Oil pumps are fine, they turn smoothly, no visible damage.
  6. overlandr

    overlandr Dystopist

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    What's the mileage on this engine again? Regardless, I would be looking for any signs of internal wear/damage on those two pumps. A feeler gauge is handy. Also a search engine should quickly reveal 'adv wisdom' on related subjects, eg try this as a search filter!

    "oil pump" feeler gauge 640 ktm site:www.advrider.com

    PS IIRC, buried somewhere on this forum are details of a rebuild of 640 following some sort of major failure. Anyway, immediately, following the rebuild, the engine failed again!! The owner this time went through everything and found an issue with the oil supply, did the 2nd rebuild and all was ok. I think,.....Others will correct me if I'm mistaken, I hope.
  7. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    Was that some sort of stuck check valve in the oil supply lines?
  8. overlandr

    overlandr Dystopist

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    As some peeps say: BINGO! 'cos I found the bugger that I was rambling on about in my post above; quoted below from Mr. Gaspipe's thread:

    "Quote:
    [Originally Posted by creeper
    So... did I miss something or what was the cause(s) of the failure?]
    Bad oil passage, then oil pump failure, followed by motor death [x 2].
    __________________
    gaspipe [the original]"


    Was post #21 in this ol' thread 'ere. May help you.
  9. Droptarotter

    Droptarotter Long timer

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    Checking all oil passages is a mandatory step in rebuilding an engine.........a little trick for oil passages or fuel passages in carbs is to blow a little smoke through them to make sure they are not clogged.

    Cheers
  10. moto_psycho

    moto_psycho Nob.

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    I've lapped all the valves etc. Crank is being pressed at the engineer's atm :rofl
  11. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    Please make sure you video a wiggle/play test like you did the first time for the bad unit. I have little to no experience with a roller/needle bearing style con rod and am curious what a good bearing looks like.
  12. Droptarotter

    Droptarotter Long timer

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    If you had seen the crank/lower con rod bearing on my Hodaka, that would have made most people tear it apart...........but the wobble/side to side play it had is just the way it is..........but no radial movement at all....so it was installed that way......and the little Wombat runs fine.

    If you send me a pm with your email address I might be able to send you the video of the Hodaka.

    Cheers
  13. gunnerbuck

    gunnerbuck Island Hopper

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    I have a pair of new cranks and a serviceable old one sitting here.. The new ones have never been used and there is very little side {or any} play at all.... The old one has more side to side movement and you can cant the rod a minimal amount, but there is no detectable bearing lift and fall {rock} as you do this... The side play is well within spec... The next time I go through my parts boxes I'll try to remember to shoot a bit of video of my old unit to add as a reference...
  14. Dolly Sod

    Dolly Sod I want to do right, but not right now

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    Hey that'd be great. I really want to get a data point for future reference.
  15. ericGSsti

    ericGSsti Been here awhile

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    How is your rebuild going.

    My mechanic finally put the engine back in mine as of this morning so should be able to collect it this evening all going well.

    Would have loved to have been able to do the rebuild myself as you are. Hope your getting it sort with out to many issues.
  16. moto_psycho

    moto_psycho Nob.

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    Interesting that you posted today! Just got my crank back at 3:30!

    Needless to say, the old one was ****ed!!!

    [​IMG]

    Engine is about half assembled atm. In the meantime I have stripped everything on the frame, the head bearings were destroyed, I've sprayed the frame orange (cheap rattle can job, there was a lot of rust) and will be waxing it on Monday. Still got to rebuild the forks, then it is just a case of re-assemble. If something goes wrong then, there will be numerous dead Austrians popping up near Ipswich...
  17. moto_psycho

    moto_psycho Nob.

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    [​IMG]

    Getting there! Spare bedroom stinks of oil n grease n ****, mmmmmmm
  18. moto_psycho

    moto_psycho Nob.

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    The eagle eyed among you will notice the lack of balance shaft in the last picture, in which, I present:

    [​IMG]

    My blank, for I really cannot be bothered to remove the bearings! (that is a cat hair, not an albino pube...)

    Will get more done later, but I'm off kickboxing in a min!
  19. ericGSsti

    ericGSsti Been here awhile

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    Great job so far. Mine has the engine back in the frame now. But the lad got call to a break down and did get it finished yesterday so won't have mine back until Wednesday due to been away from work.
    [​IMG]

    Great to even see the engine back together. My failures where a mirror image of yours except for the crank bearing. Mine was fine but my main had been distroied. I used all original KTM parts and a mechanic to put mine right. Cann't wait to have it back.
  20. ericGSsti

    ericGSsti Been here awhile

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    I saw this thread go up the day my engine failed so following a similar path. :norton

    Even needing fork seals done.

    Best of luck with the rest of the work on yours.