LC4 640 starter clutch fix

Discussion in 'Thumpers' started by losiu, Apr 17, 2007.

  1. exman

    exman amateur-enthusiast

    Joined:
    Jul 17, 2011
    Oddometer:
    17
    Location:
    Belgrade, Serbia
    That's the answer! All my doubts are gone! And Gunner completed the theory with his notice about how bad battery can contribute to the excessive wear of the clutch components. And what's more: after reading your posts, I checked Tseta's article about How to service suspension on LC4, and enjoyed all those beautiful landscapes of B.C. posted by Gunner. Not bad for a newbie in just one afternoon. Thanks guys.
  2. bmwktmbill

    bmwktmbill Traveler

    Joined:
    Jul 16, 2005
    Oddometer:
    5,610
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    The real deal from KTM

    [​IMG]

    Red loctite, 95psi broke it, this is the wrong way to do things but it is quick.

    [​IMG]

    Looks good.
    [​IMG]

    Is good.

    [​IMG]

    Put back in service.
    Torqued with the air wrench, again the wrong way.
    bill
  3. 2wheelsrbest

    2wheelsrbest Been here awhile

    Joined:
    Jun 23, 2007
    Oddometer:
    356
    Location:
    North Central WA
    Sprag clutch is out
    Boss picked up ring with teeth in it, which all fell out

    anyone have a good picture/diagram showing which way the teeth fit inside the retainer ring?

    I realize there are only two possibilities, but do enjoy getting it right the first time.

    Thanks to everyone who...

    pointed me to this thread
    took a picture of what they were doing
    shared their alternate fix experiences
  4. slackmeyer

    slackmeyer Don't mean sheeit. .

    Joined:
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    Berzerkeley, CA
    Crap, I should have taken a picture of that. I just fixed my clutch. I'll just say that it did take two tries, but that second try went pretty quick once I had some practice.

    I just shortened the OEM spring by about 3/4", no need for a new one for me.
  5. 2wheelsrbest

    2wheelsrbest Been here awhile

    Joined:
    Jun 23, 2007
    Oddometer:
    356
    Location:
    North Central WA
    Ok, I will answer my own question using bmwktmbill's pictures above.

    The 4th picture shows the retaining ring and the teeth well enough. Retaining ring has two different edge patterns to the metal--inboard edge is different than outboard edge. Match it up with the picture and orient the teeth such that the notches/lips on the outer, grooved edge are all pointing the same direction. Pic is a little fuzzy, but shows it clear enough.

    The 3rd picture, as well as losiu's on post #1 shows the orientation of the assembled sprag clutch to the motor. Put simply, the side with the snap ring (shown well in post #1) goes in, toward the motor.

    I used an SKF 19992 spring, which was what I had available ($10, locally) and it works fine. It is significantly smaller in circumference than what came out, but I don't know what OEM looked like originally.

    My recap--

    97 Duke 620-E, <7k miles
    33mm puller, Motion Pro #08-0390, M33 x 1.5 RH IT, fwiw Parts Unlimited or Tucker Rocky (I forget) had different part number of 158089, $40 Seattle Cycle Center (Yay!)
    24mm left-hand crank nut @ 132 ftlbs
    no crank lock bolt that losiu mentioned
    puller provides anti-rotational holding power for pulling action
    no new gasket needed, no oil lost
    SKF 19992 seal spring used

    *Same puller works on
    Suzuki GSXR 1000 01-08
    Suzuki GSXR 600 01-09
    Suzuki GSXR 750 00-09

    Yamaha WR450F 04-11
    Yamaha YFZ 450 04-09
    Yamaha YFZ 450 12

    ^In case you run into a mechanic who doesn't know he has a tool that will work OR have a terrible time finding a tool listing when trying to order.
  6. MNCherryinCA

    MNCherryinCA KTM Noob

    Joined:
    Mar 13, 2011
    Oddometer:
    577
    Location:
    Santa Clarita, CA
    Hey All,i am going to attempt to put in a new sprag from KTM this weekend/week. I will take lots of pics and post a report on the LC4 index.
  7. shiftylukbast

    shiftylukbast n00b

    Joined:
    Jul 16, 2012
    Oddometer:
    1
    Hi, I know this is quite an old thread, but I would just like to say thankyou Losiu. Followed the excellent photo guide on my '05 640 Supermoto, came up with a sprag spring in exactly the same condition, put in the new oil seal garter spring and my starter sounds brand new. :clap
  8. MNCherryinCA

    MNCherryinCA KTM Noob

    Joined:
    Mar 13, 2011
    Oddometer:
    577
    Location:
    Santa Clarita, CA
  9. DirtBikeDaddy

    DirtBikeDaddy DBD

    Joined:
    Dec 11, 2010
    Oddometer:
    16
    Location:
    Thumper
    Well I've finally sat my A55 down and put some time and $ into doing this repair...to tell you the truth I got tied of kick starting the beast...Grrr
    Like all you fine blokes have told me, it was simple with the right tools.
    I too have a 26mm flywheel tool for sale, hahaha, but the 33mm arrived friday!

    No pictures sorry, but the spring is toast, not just stretched but flattened in multiple sections...
    I'm going to pick up one of those SKF seals and give it a go.

    I have one questions;
    My spraugue assembly is showing signs of wear, the little bits have flats and rough spots, but the shaft is clean and smooth.

    Would the sprague assembly work if I flipped the individual bits around, kind of swap the gouged/rough surface for the smooth ones so to speak?

    I did note the unit has a directional arraow on the inside surface but I'm just being cheap, because the replacement part is listing for $107.00 CDN plus all the TAX, shipping, etc...etc...I'll be lucky to get it in my hand for under $200.00!

    Thanks for ALL the help...this old newbe really appreciated it :photog
    Cheers
    DBD

    One last thing...details
    KTM 2004 SMC 11,000
  10. gunnerbuck

    gunnerbuck Island Hopper

    Joined:
    Nov 19, 2005
    Oddometer:
    5,140
    Location:
    N.V.I, B.C.
    It very likely would not work in any other way than the way it was designed.. The tumblers have a cam profile that wedge out to grab the drum while at the same time gripping the raised machined surface on the gear with the underside..

    You could give it a try and see what happens...

    The sprague is $65 at parts pit stop
  11. slackmeyer

    slackmeyer Don't mean sheeit. .

    Joined:
    Jul 23, 2007
    Oddometer:
    3,626
    Location:
    Berzerkeley, CA
    I gave it a try (accidentally) Doesn't work, the cams don't grip. I knew it was a one way thing, but I didn't pay enough attention when taking it out. . . . live and learn.
  12. AEsco48

    AEsco48 Adventurer

    Joined:
    Dec 3, 2007
    Oddometer:
    63
    Location:
    Cairo, Egypt
    Hello.... Does this sound like a sprague clutch issue? Bike starts up fine after a quick push of the e-start button...

    In the below video I had run out of fuel.

    http://youtu.be/rjISVTSAGYI

    Any ideas?
  13. DirtBikeDaddy

    DirtBikeDaddy DBD

    Joined:
    Dec 11, 2010
    Oddometer:
    16
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    Thumper
    Even on an empty tank yours sounds alot better than mine!

    If your bike starts I'd say you have no problems, but if the noise gets louder or you hear any sliping it might become a problem.

    Cheers
  14. DirtBikeDaddy

    DirtBikeDaddy DBD

    Joined:
    Dec 11, 2010
    Oddometer:
    16
    Location:
    Thumper
    Thanks for the info, I have a seal on order to replace the spring.
    I plan to just file down the worst of the rough spots and give it a try.
    My season is almost over anyways, along with my temp. license...lol

    Now that I have the tools, it's not such a big deal replacing the assembly if the spring dosn't work.

    Cheers
    DBD
  15. 5-0 BAIT

    5-0 BAIT n00b

    Joined:
    Aug 1, 2012
    Oddometer:
    7
    Location:
    HONOLULU, HAWAII
    So, I'd like to thank Gunnerbuck for showing me the light & sending me to this thread. I'll also post pictures of my little adventure, and let everyone know if this is the surgery my bike needed. Boy howdy I tell you what.
  16. bmwktmbill

    bmwktmbill Traveler

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    5-0 Bait,
    Take plenty of pictures, wish I would have done a better job when mine was apart for the benefit other inmates.
    bill
  17. philosobrad

    philosobrad problem_solvent

    Joined:
    Sep 5, 2006
    Oddometer:
    173
    Location:
    Springfield, MO
    I understand that different year LC4 engines require a different magneto puller in order to get to the sprag and fix it. Can anyone verify that this part number: 58429009000 is correct for a 2001 640 Adventure?
  18. bmwktmbill

    bmwktmbill Traveler

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    Brad,
    That's the number for the puller I used on my '02 640 adventure.
    I own it. Pictured on the previous page.

    Want to borrow it?
    bill
  19. philosobrad

    philosobrad problem_solvent

    Joined:
    Sep 5, 2006
    Oddometer:
    173
    Location:
    Springfield, MO
    That would be awesome. Let me know how to handle logistics.
  20. bmwktmbill

    bmwktmbill Traveler

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    Oddometer:
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    Brad,
    First swear an oath on your Owners Manual.

    "KTM, grant me the serenity...."

    Send me a PM with your address.

    I will mail the puller to you, you pay me the postage and mail it back.

    bill