Aaarrrrgggg!!! damn base gaskets....

Discussion in 'Thumpers' started by laramie LC4, Sep 29, 2006.

  1. laramie LC4

    laramie LC4 flying something...

    Joined:
    Sep 19, 2004
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    2,924
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    easier said than done. there is no way to access 2 of the head bolts without removing the rocker cover, which is a pain in the arse.

    i think its going to be OK, but i guess only time will tell. so ill cross my fingers and see what happens.

    on another note, hopefully you can make it in Jan. it promises to be a wild ride with some pretty awesome terrain. much more technical than the last one. looks like there will be a good portion of single track every day. still not finalized but if i got anything to say about it (which i do, im trail bossing the thing) we will be doing some great high speed, watch your ass, cactus infested, single track. maybe even doing the national harescramble loop that i raced last Jan. :evil

    laters,

    laramie :cheers:
    #21
  2. bmwktmbill

    bmwktmbill Traveler

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    Coming to a KTM from a BMW airhead I wondered about retorquing the head. With BMW they suggest checking it with every valve set, I think we did it every 10K miles or so. I know it isn't the right way but we never loosened the head bolt nuts, just checked torque tightness. Occasionally one would take a little.
    With a fresh motor, if it was me I would re tighten the ones I could get at at the very least and maybe bite the bullet and get at them all.

    Another thing we did with Beemers after torquing the head on a rebuilt engine was to let it sit over night and check torque a second time in the morning. The bolts always took more...always.
    And we never leaked, never.
    Knock on wood.

    Bill in Tomahawk, WI
    #22
  3. meat popsicle

    meat popsicle Ignostic

    Joined:
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    photos... should I shut up yet? :lol3
    #23
  4. bikemoto

    bikemoto Tyre critic

    Joined:
    Oct 24, 2004
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    4,211
    Location:
    Nelson, New Zealand
    Thanks Laramie, I read this with interest before tackling my own base gasket leak. Well, err, the bike's one :eek1 See Fixing the 640 base gasket, and more...

    Okay, my bike is a 2005 Adventure (EU/AU). As you can see from the picture, it has small base dowels:

    [​IMG]

    Here's the cylinder base, showing the stain from the OEM paper gasket - Part num *586.30.035.100, CYL. BASE GASKET 0,5MM 05 - including the area that split then leaked (circled).

    [​IMG]

    And finally, here's the superseding metal base gasket - Part num 586.30.035.200 CYL. BASE GASKET 0,5MM M.SICKE - overlaid on the cylinder base. Pretty good match for a newer bike. This gasket has a "made in USA" sticker on the package, so is probably the Cometic gasket.

    [​IMG]

    The KTM repair manual advises putting sealant around the camchain tunnel area.

    Mine failed because the paper gasket walked out of the join, and split. Can't tell which order those two things happened! But I guess the metal gasket won't suffer the same type of failure.
    #24
  5. laramie LC4

    laramie LC4 flying something...

    Joined:
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    looking at the pics i would agree, that is a Cometic gasket. i wish i could get one to fit correctly because my paper one is already leaking again. next time i think the surfaces are going to have to be re-done to match them back up. this is frankly just ridiculous to have to replace such a basic, fundamental gasket so often. granted all it really does is make a mess and looks really bad. the oil loss is nominal and if you check often, isnt really a big deal. im just one of those people though that hate leaks. i think the only reason i havent torn it back apart again is that im sick and tired of dealing with it. its cheaper and easier for me to just wash the bike and pretend nothing is wrong.......:baldy

    good luck with yours.

    laramie :beer
    #25
  6. bikemoto

    bikemoto Tyre critic

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    Ta.:freaky

    Sounds like you might be best to make the metal gasket fit. Mine was a weep for quite a while, sometimes staying dry for a couple of days after a clean. Then it turned into a gusher in a handful of km.
    #26
  7. dtysdalx2

    dtysdalx2 Knowledge is horsepower

    Joined:
    Aug 1, 2004
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    22,781
    Location:
    Moneyapolis, MN
    Those MLS gaskets are the sh#t. I just replaced the base on my XT, used a Viton O-ring instead of the Buna-N stocker. Then I used anaerobic sealant on both sides of the fiber gasket to hold it in place. VERY thin on the sealant. Hopefully I will die before it leaks again. I did it on the cheap instead of the MLS gasket though.

    The Cometic head gasket didn't fit quite right, so I trimmed it with a scissors. Saved $50 bucks though.

    Man, I'm a hack!
    #27
  8. cyclewizard

    cyclewizard Long timer

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    Norway/Michigan.
    I hope that gasket never leaks, we will miss you around here D.T.:cry
    #28