oil leaking at headstock cover
Close
Login to Your Account
Results 1 to 8 of 8
  1. #1
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    509
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    64

    Default oil leaking at headstock cover

    I have been able to eliminate just about every leak except for the headstock cover. I originally had a new cork gasket from Monarch. Leaked. I cleaned the cork and reinstalled with Hylomar both sides. Leaked. I have made two new gaskets from different thickness material. Both leak.

    The tach gears sling the oil so energetically that the oil starts weeping where the arrow is, and then the leak slowly progresses around the entire cover.

    I traced this because I had oil wicking between all the covers, and in cleaning all the oil off and watching, it turned out that this leak was the cause of all the wicking.

    Is there any way to seal the cover plate? I guess my next solution would be silicone seal like on a car engine oil pan.

    img_0937.jpg

  2. #2
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,581
    Post Thanks / Like
    Likes (Given)
    791
    Likes (Received)
    1889

    Default

    Yamaha used to, and may still, make (probably just private label, really) a product called Yamabond. It was a non-hardening sealant meant for sealing dirtbike cases that couldn't have a traditional gasket. I wonder if that's a candidate?

    ETA- it appears they still make it, Yamabond 4.

  3. #3
    Join Date
    Feb 2019
    Country
    UNITED STATES
    State/Province
    Michigan
    Posts
    161
    Post Thanks / Like
    Likes (Given)
    43
    Likes (Received)
    42

    Default

    Have you put the cover on a surface plate, upside down and looked to see if the cover is not flat, but distorted by the fasteners pulling it against the soft gasket material and making the cover have a high spot or weak-tension spot where the leak is?
    You might be able to make the cover flat again or even better, a slight curve against the leaking location; a bit of added tension at the leak location. and try again with a new gasket and a good sealant.
    The problem is not a fault of the gasket or the sealant, it is lack of proper pressure or tension in that location.

    Several additional ways to stop the leak at that location:

    The best way and the most professionally appealing way: drill and tap an extra hole and add a screw there. There is too much distance and not a straight line between the two fasteners adjacent to the leaking location.

    You could see if you could make a splash shield that protected the leaking location from a direct spray off of the gears. Rivet or weld the spray-shield to the underside of the cover.

    Use longer fasteners at the two adjacent locations and make an aluminum 'bridge' to span between them, Make this bridge at least 1/4" thick so it will not flex easily like the cover does. The bridge could have a slight bump in the middle over the leaking location to add additional pressure there.. Just a few .001"s.

    Or: dry off the metal and gasket surfaces, clean of all oil. Use Permatex Ultra-Black or Grey sealant/gasket maker with a new gasket. Give it 24 hours to set. Do not use an excess amount, you don't want blobs of excess sealant to be in the gear box.

    DualValve

  4. #4
    Join Date
    Mar 2011
    Location
    Geneva Illinois USA
    Posts
    6,273
    Post Thanks / Like
    Likes (Given)
    2712
    Likes (Received)
    2424

    Default

    Unless this a frequent removal point, I would just silicone it and be done with it.

    Tom

  5. Likes LKeithR liked this post
  6. #5
    Join Date
    May 2003
    Location
    Walla Walla Wine and Wild Turkey
    Posts
    4,668
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    357

    Default

    That Yamabond is a remarkably good sealant! My 51 ee has a flat sheet metal splash plate with a round screen located just under the filler hole. It still has a dry gasket on the heavy iron top cover, the splash plate seems to prevent oil from seeping out.

  7. #6
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    509
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    64

    Default

    The Yamabond description sounded a lot like the Hondabond I used on my 1996 Integra, which did work well. After a bit of searching I find that Yamabond is the same product as the Hondabond, and I fortuitously still have an almost full tube sitting in the garage, so that will be my next attempt.

    Thanks for the advice.

  8. #7
    Join Date
    Jun 2007
    Country
    UNITED STATES
    State/Province
    Nevada
    Posts
    509
    Post Thanks / Like
    Likes (Given)
    1
    Likes (Received)
    64

    Default

    Update - I used the HondaBond, with 1 mm spacers between the casting and the plate when I pressed the plate into the Hondabond.

    No leaks.

    Thanks for the suggestion.

  9. #8
    Join Date
    Sep 2011
    Country
    UNITED STATES
    State/Province
    Virginia
    Posts
    28,169
    Post Thanks / Like
    Likes (Given)
    7561
    Likes (Received)
    8718

    Default

    Quote Originally Posted by donie View Post
    That Yamabond is a remarkably good sealant! My 51 ee has a flat sheet metal splash plate with a round screen located just under the filler hole. It still has a dry gasket on the heavy iron top cover, the splash plate seems to prevent oil from seeping out.
    Same with the older 1940's "round dials" here.

    This simply should NOT be a problem. The OEM cork gasket "JFW" even if old and unreplaced.

    "One wonders" if..

    - The OP is MISSING the inner sheet-metal shield? Or the bronze screen?

    - has a damaged one? of either?

    - has a badly-made DIY one (they are dirt-simple to make - only "hard" part getting all those silly HOLES right. Any stock screen will do.)

    Or even has a dirty sight glass ...and has simply overfilled the lube supply?

    Besides... totally DRY machine-tools are akin to totally dry... sex. Or even taking a dump.

    As with "Pee air", the dehydrated French alcoholic who overdid it when giving up wine to dry himself out, that's "be careful what you wish for" territory?



    Whole BUNCHA stuff as is more important to getting to where yah can make some chips..


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •