2003 KLX 300r: What’s that noise??

Discussion in 'Thumpers' started by biles430, Dec 11, 2020.

  1. biles430

    biles430 Adventurer

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    Hi all!
    Just took the dive on buying a CL bike with a strange engine noise as a new COVID project, because why not! Have gone through the forum reports I could find on Kawi KLX engine noise and haven’t found a smoking gun yet.

    Attached here is a link to a video of the bike idling. Bike was warm when video was taken.


    Diagnosis so far:
    Pulled cam chain tensioner and checked function of automatic tension mechanism, looks good.
    Pulled valve cover, examined cam chain tension with and without tensioner installed and tension feels good.
    Checked valve clearance and all checks out.
    Ran around the block a few times to really get things moving and noise stay consistent and idle and through rpm, slight increase in tone with rpm.

    I have heard this is a noisy motor but previous owner seemed to think it shouldn’t be this loud and so I dont have a baseline.

    Going to continue hunting but stumped on what to check next before pulling the motor and splitting the case to check bottom end bearings. Any thoughts would be appreciated!
    Cheers!
    #1
  2. webmonstro

    webmonstro A Aventura Continua....

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    Spunds like a bearing. could also be cam journals
    #2
  3. Johann

    Johann Commuterus Tankslapperus

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    Idler gear between kickstart and clutch. They are a design problem on that engine, if it goes completely the parts can end up everywhere. You need to pull the clutch to check, look for play on the idler gear and missing/damaged teeth, plus missing damaged teeth on the back of the clutch. If you´re lucky the debris will still be on the clutch side of the engine. Don´t run the engine any more until you´ve had the clutch off to have a look.
    #3
  4. biles430

    biles430 Adventurer

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    Thanks both for the thoughts!
    Checked cam journals and they look good.
    9CE74852-125F-433B-9175-57A45AC79397.jpeg
    F1476FFC-9404-458E-B42B-883BDE549A82.jpeg

    Oil is draining and currently breaking into the bottom end and pulling clutch.
    Greatly appreciate the thoughts!

    Is the best solution replacing the idler gear with an OEM one or as there been a doo-hickey style fix?

    Cheers
    #4
  5. Johann

    Johann Commuterus Tankslapperus

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    It´s complicated. If it is the idler gear the problem is the bushing on the inside of the gear wears leading to the play. There was a guy somewhere selling modified gears but I don´t think he is in business any more. The best solution might be to find a friendly machine shop, explain the problem and see if they can improve the bushing on the OEM gear. I´ve got one in the yard at the moment and some secondhand spares to get it running again but I don´t know if I want to without being able to confirm the same thing is not going to happen 5k miles down the road. If you do find a good solution please feel free to share it.
    #5
  6. biles430

    biles430 Adventurer

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    Johann, Thanks for the thoughts!
    More for ya.
    Pulled the clutch and clutch basket and could not find any play or slop in the idler gear. I assume the idler gear is the gear connecting the kick-start to the clutch, correct? Either way all looked and felt good but there is some interesting scaring on a section on the right side. See below.

    ACCCDD02-46E6-4386-9170-C1A384A9FAED.jpeg
    92DE2FF2-61A8-486A-A08A-1258F893733D.jpeg
    B324F5C2-D086-40AA-BB96-17DA12F7DECF.jpeg

    Seems there may of been an inappropriate rebuild be previous owner... thoughts?

    Thanks!
    #6
  7. Johann

    Johann Commuterus Tankslapperus

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    #7
  8. Navin

    Navin Long timer

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    Stick a tool in that clutch shaft and check the bearing for play.
    #8
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  9. Johann

    Johann Commuterus Tankslapperus

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    I think there´s another bearing inside the clutch hub. Any play on that?

    ETA: Double check in the manual/fiche but I think there is supposed to be a thrust washer that goes on before the basket, if that was missing it could explain the contact as well. I can see a washer in your photo but worth checking the order.
    #9
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  10. NorthernTraveler

    NorthernTraveler Long time Adventurer

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    The idler gears went because the early bikes had an improperly timed de-compressor on the exhaust cam.
    It put excessive load on that idler gear when kicking.
    I had a '94 where it broke the end off of the counter-shaft that the idler rode on.
    There used to be a guy on PlanetKLX that re-timed my de-compressor.
    That site is gone, but there is a mod being done now - the Marselo mod? - that shows how is should be timed.

    I kinda think your's is new enough that it shouldn't be a problem, but I'm not sure.
    #10
  11. biles430

    biles430 Adventurer

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    Bushing looks good on idler gear and no play in clutch bearing and clutch teeth look good.
    There is a washer missing, which as stated would put contact between clutch basket and bottom mounting point of cam chain guard/tensioner. HOT on the chase! Of course no washer available locally, so currently engaged in some custom spacer “fabrication” to see if this is our culprit.
    Will report back.
    Cheers all
    #11
  12. biles430

    biles430 Adventurer

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    Just to finish it all off and conclude:
    Thrust washer inside of clutch basket was missing. Purrz like a cat now! (Rather loud cat...)


    Thanks all to for the help!
    Once we make it to the other side of these times and anyone ends up in the NorCal area I’d love to meet up for a ride!
    Cheers
    #12
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