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Thread: Head Gasket Replacement Technique - MLS

  1. #1
    Senior Member pdksh's Avatar
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    Head Gasket Replacement Technique - MLS

    I have a 2008 XB12 with a head gasket that is leaking oil, drip.... long pause drip... No hot gas blow by as best as I can tell and the bike runs great. I have ordered a James Gaskets top end gasket kit. The kit has an MLS head gasket and a standard paper/metal gasket. I'm going to assume the MLS gasket is the way to go. I am looking for the proper technique to install a James MLS head gasket. I see lots of posts about installing sportster head gaskets on google, when a sporty pumps out more than 30hp I'll start taking them seriously ;-)

    - Do I drill out the rivit?
    - O-ring vs no-oring?
    - 1/4 turn on the head bolts vs torque sequence
    - oil/lub head bolts?
    - lock tight head bolts?
    - hot glue gun or ladies nail polish
    - etc, etc, etc

    The reason I ask is, a year ago I did the base gaskets because of oil weep (still weeps) and obviously I did the head gaskets and rocker box gaskets. The rocker box does not appear to be leaking. I have doubts about the quality of install I did a year ago. I may have used the o-rings. I may not have properly lubed the head bolts. Every year I'm rotating the engine for gaskets, getting pretty good at it - BUT if someone can offer suggestions and comments I'm all ears. Maybe next spring I won't have to rotate my motor. Maybe I should install velco fasteners...

    I could blame James gaskets but I don't think its them :-P (this time)

  2. #2
    Senior Member Cooter's Avatar
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    MLS gaskets are better, use them.

    1)What rivet?
    2)always replace O-rings (might as well replace a 2˘ part in your hand)
    3)always torque sequence, and always the recommended procedure. You can't torque turn bolts when 4)you only have a final torque setting number and vice versa Manual: http://buellmods.com
    5)lube the threads on the head bolts with oil like the manual says^^^
    6)Paint your nails black, only the cool guys do that.

    Just follow the easy to follow procedure in the manual link I gave you. No need to re-invent the wheel here, just keep it all very clean, follow every step, and ignore the old-wives tales from ex-Harley mechanics from the 60's

  3. #3
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    On some of the head gaskets made from several layers, there are rivets to hold them together. You can see the rivets on the top and bottom.

    97B242E6-3E4A-4DE7-9021-08501AEF020F.jpg

    Using orings around the head studs was a common practice at some point. I think the newer gasket sets (Cometic) are designed not to use them. I’d recommend reading the instructions to see what the case is for your setup. With my Cometic head gaskets, both they and NRHS recommended not to use orings. As far as torque pattern, spec and oil or not, the Cometic instructions were pretty thorough about how they wanted it done. If it was HD OE gaskets, i’d just follow the HD service book, as the design between stock head gaskets and the Cometic were pretty different.

    If you haven’t bought them yet, I’d recommend hitting up Dan over at NRHS or the other forum.
    Last edited by 34nineteen; 05-20-2019 at 07:34 AM.

  4. #4
    Senior Member Cooter's Avatar
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    Oh, those rivets...

    No. Don't drill them.

  5. #5
    Senior Member pdksh's Avatar
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    so I have a very good idea of what went wrong. I used the James gasket kit but did not use the o-ring locating gasket, I think... I need some input from someone more familure with the James Gaskets for a sporty/buell motor. Clearly the front head gasket failed and the rear gasket looks like it was also weeping.

    front head gasket
    IMG_1890.jpgIMG_1891.jpg

    rear head gasket
    IMG_1892.jpgIMG_1893.jpg

    The gasket kit does not include instructions. It does list a Gasket, Cylinder Head, 1200cc x2 and O-Ring, head gasket locating x2 so I assume that means I need the locating o-ring???

  6. #6
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    From Wisecos instructions:

    6. If using a head or cylinder other than stock, check the brass rivet locations to ensure the rivets do not interfere with the sealing surface in any way. Some aftermarket castings are substantially larger than stock castings and may interfere with the rivet location.

  7. #7
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    Also from Wiseco’s instructions:

    MLS Head Gasket Instructions for Harley-Davidson® applications
    NOTE: Do not use the cylinder head alignment dowel O-ring when using an MLS gasket.


    You may want to search James web page or call to see if the same applies to their gaskets.

  8. #8
    Senior Member Chicknstripn's Avatar
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    I don’t remember head gasket replacement being this much drama when I did mine. I just followed the service manual. Only thing I did differently was I liberally coated the gaskets with holymer blue. I also omitted my base gaskets(to set a real tight squish band) by using only holymer blue between the cylinder and case.

    Are you following the service manual?
    Have you contacted the gasket manufacturer or supplier as has been suggested?

    I wouldn’t button anything up until you’re 100% sure you’ve got it right.

    I just remembered one issue I did have with an oil leak after my rebuild. The seals at the top of the push rod cover got pinched during installation and therefore caused a leak. Be careful and watch out for this when reinstalling the push rod covers and heads.
    Last edited by Chicknstripn; 05-20-2019 at 10:50 PM.

  9. #9
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    Quote Originally Posted by Chicknstripn View Post
    I don’t remember head gasket replacement being this much drama when I did mine. I just followed the service manual. Only thing I did differently was I liberally coated the gaskets with holymer blue. I also omitted my base gaskets(to set a real tight squish band) by using only holymer blue between the cylinder and case.

    Are you following the service manual?
    Have you contacted the gasket manufacturer or supplier as has been suggested?

    I wouldn’t button anything up until you’re 100% sure you’ve got it right.

    I just remembered one issue I did have with an oil leak after my rebuild. The seals at the top of the push rod cover got pinched during installation and therefore caused a leak. Be careful and watch out for this when reinstalling the push rod covers and heads.
    I agree... I just followed the instructions to the "T" and it was easy peasy lemon squeezy. Of course, it was on my 2016 Roadster, so it was really easy.

    I did have a similar slight mishap and had one of the pushrod tube orings get dislodged from the groove in the pushrod tube block. But still wasnt that bad. If I had that happen on my XB, I'd probably cry a little. (ok, a lot... I'm a wuss).

    This is the NRHS version of the block, but you get the idea.

    Last edited by 34nineteen; 05-20-2019 at 11:57 PM.

  10. #10
    Senior Member konarider94's Avatar
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    Quote Originally Posted by 34nineteen View Post
    From Wisecos instructions:

    6. If using a head or cylinder other than stock, check the brass rivet locations to ensure the rivets do not interfere with the sealing surface in any way. Some aftermarket castings are substantially larger than stock castings and may interfere with the rivet location.
    This is correct but its not just aftermarket. I had to take out one of the rivets with stock components. Its pretty easy to tell if a rivet is going to prevent the surfaces from coming together or not.

    I followed the torque sequence per the manual and did not use o-rings as instructions with the gasket stated.



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