Oz/Kiwi KTM 640 ADV riders sign in here please.

Discussion in 'Australia' started by overlandr, May 10, 2006.

  1. motolab

    motolab Long timer

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    Keep in mind that 38 degrees BDC at 6000 rpm is a single line of breakpoints on a grid, and that the entire remaining portions of the maps could be significantly different.

    Regards,

    Derek
  2. GodSilla

    GodSilla I did that.

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    I understand that Derek. Once the motor hits 6000rpm and then higher there should be no difference, that's what I'm thinking. I don't so much care how it gets there as long as it gets there, this isn't being developed for street use, just full-noise operation.
  3. bikemoto

    bikemoto Tyre critic

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    Yes, one data point doesn't tell you much about the entire curve.
  4. GodSilla

    GodSilla I did that.

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    But my question still stands :
    .......... if I'm running a 41mm pumper on an originally-equipped 39mm BST bike, if they all top out at the same advance at the same revs (same cam, why not?) does it matter if all I'm gonna do is accelerate through the gears and then hold it flat for a mile?
  5. dnrobertson

    dnrobertson Big Bike, Slow Rider

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    I guess potentially the settings could be so off (i.e. tuned for the BST) with the FCR that you could detonate the engine to death before you get it flat out in top.
  6. enookway

    enookway Are we having fun yet?

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    Topic diversion back to airbox's

    I take it no-one has a spare big filter airbox laying around before I buy one off Gumtreebay?
    GodSilla likes this.
  7. Brendo404

    Brendo404 Adventurer

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    I didn't measure them but I do recall seeing them there still. One of the circle ones were just starting to show some wear.
    I'll give it another look when I replace the airbox.
  8. motolab

    motolab Long timer

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    What does it look like (i.e. what about the appearance makes it look worn)?

    Regards,

    Derek
  9. Brendo404

    Brendo404 Adventurer

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    It had less of a depression, was also uneven.
    The slide itself also showed some wear, but no scratches or gouges.
  10. motolab

    motolab Long timer

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    Just so you know, the round depressions don't start disappearing until late in the game (i.e. when the slide guide is already well past the point of replacement).
    No vertical grooving on the downstream side? Have the slide lift holes been drilled?

    Regards,

    Derek
  11. Brendo404

    Brendo404 Adventurer

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    Oh ok, thanks. Just didn't appear that bad to me.
    I'll add one to the parts list of things to buy.
    There were visual marks on the slide but nothing that could be obviously felt with a fingernail.
    Slide holes are 2.5mm, so I assume not drilled.
  12. motolab

    motolab Long timer

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    Like I said, the ones in the bottom corners should be measured. They start out 0.5 mm deep, and emulsion tube wear sets in when they are 0.25 mm or fewer deep.
    Without seeing it, I'd probably recommend replacing it if the guide is replaced, just to keep it from accelerating wear on the new guide. Can you post up a picture?
    Excellent.

    I saw the picture of your cut airbox. With its tendency toward detonation problem, the engine won't tolerate that much of an increase in cylinder filling (unless adequate countermeasures are undertaken). For example, a high flow head model such as yours will tolerate snorkel removal and race lid installation as long as the exhaust system had been upgraded via Akrapovič or Leo Vince slip-on without quiet insert, and jetted correctly.

    Which brings me to your float height adjustment. Low rpm operation becomes too rich across the board (but with a stronger effect the larger the opening) when the correct main jet is installed to accommodate reductions in airbox inlet restriction. This can be compensated for to an extent via an increase in float height. Perhaps that is why the PO set the float so high.

    A more likely explanation is that it was an amateurish attempt at addressing an (perhaps intermittent) overflowing problem.

    Inspect the tip of the float needle with and without magnification to see if it has a witness line where it has been contacting the seat. If so, it should be replaced. Float needles with witness lines cause a higher fuel level, which in turn causes a richer mixture (and at some point overflowing). Therefore:

    Replace the float seat o-ring if it does not fit snugly or is hardened/deformed/shrunken/cracked/otherwise damaged. A leaky float seat o-ring causes a higher fuel level (and at some point overflowing), which in turn causes a richer mixture.

    If both the float needle and needle seat o-ring are in need of replacement, it's probably best to just get a rebuild kit, as the rest of the rubber parts are likely to also be in poor condition (for example it's pretty much guaranteed that the slide guide o-ring and the fuel screw o-ring will be smashed flat).

    Inspect the float hinges for wear (pins should be round instead of lozenge shaped, bores should be round instead of oval.

    Make sure the float is not fuel logged (should weigh 6.1g or fewer when separated from the cage).

    Regards,

    Derek
    Brendo404, GodSilla and robmoto like this.
  13. Brendo404

    Brendo404 Adventurer

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    Oh wow, thanks mate!
    I will post pics when I have it apart again, hopefully sooner than later.

    Yeah, I'm not keen on this hacked up airbox at all!
    It still has the std pipe on it, I'll be looking into changing it soon too.

    To the naked eye the float needle and seat looked fine, but I'll have a closer look when I get back in there next.

    Float seat o ring also seemed fine.
    But if it's available as a kit to replace them all, I'll probably just grab that and do them all anyway.

    I'll give the float and float hinges a better look too.

    It does run noticeably better now than it did before, not that it was super terrible before.
    But I do feel it could be better still.

    Another question I have is about kick starting them.
    I cannot for the life of me kick start it, cold or hot.
    And I've followed the guide on here about how to.


    Thanks.

  14. explodingmouse

    explodingmouse Been here awhile

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    thats weird , the 03 that I used to have was the easiest bike to kickstart that I have ever owned , had a Honda xl250r years ago that was much harder.
  15. GodSilla

    GodSilla I did that.

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    I'm well versed in starting my XR6, but it took a fair bit of practice to get the KTM to fire as easily. The basic technique is the same, but subtly different. The left-side kickstarter requires familiarisation too but I actually like it.
  16. GodSilla

    GodSilla I did that.

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    I might have asked this previously but I can't find it anywhere, so I'll ask here.

    What diameter is the axle on the front & rear of a 2003 640 Adventure?
  17. enookway

    enookway Are we having fun yet?

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    Did 03's have the 43mm forks? If so then 20mm axle.
    04 Adv went to 48mm forks (and twin disc) so 26mm axle
  18. rvt

    rvt Big Fat Trail Bikes

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    This method was shown to me by two excellent fellows, Jack and Ross. Refined a bit to suit me. Be sure to wear suitable boots in case it kicks back. Hasn't happened to me, but I have heard the consequences can be nasty.

    1. Bike in neutral. Fuel tap on. Bike not on stand. Hold decomp in, give five or so full kicks.
    2. Release decomp.
    3. Key on, kill switch on, choke on if engine cold. MX boots on!
    4. Slowly operate the kick until you hear the auto decomp click.
    5. Apply just enough pressure to rotate slightly more. Just past tdc, where the pressure in the cylinder starts wanting to push the piston down. Not too far! If it goes too far, start again from step 4.
    6. One big, full stroke kick. Standing next to bike, using right foot, body facing slightly to rear of bike. I found grabbing the pannier frame and pulling the bike towards my foot helped a lot.

    This works well for me, even if the bike has sat for a couple of weeks.

    Good luck.
  19. GodSilla

    GodSilla I did that.

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    Cold morning here, frosty. While the bike cranked over just fine, it wouldn't fire. It has been sitting for 4 cold weeks, and I've had the battery turned on to test lights, horn, etc. so maybe I took the edge off it.

    One kick though and it fired up, perfectly.:clap
  20. GodSilla

    GodSilla I did that.

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    Got an answer in Thumpers thanks.
    It confirmed I have 20mm front and back (on a 2003 single-disc 48mm WP front end).