Fatboy EVO leaking oil

Discussion in 'Softail Models' started by White Mts. Rider, Jun 18, 2009.

  1. I posted a few times before on an old thread about a my EVO leaking oil and asked if anyone had any thoughts. After a few suggestions I changed the umbrella valves in the rocker boxes, as suggested, with no luck correcting the leaking. Another suggestion was change the air cleaner, so I did that, putting on a new Ness Big Sucker Stage II, but that didn't help. So I figured that I would start from the top on the cylinder heads and replace every gasket there was in the rocker boxes. Well I got the boxes off and if the pictures come out I'll show you the gaskets that are between the boxes and the cylinder head. They have shrunk up so much that the holes for the bolts and oil ports have become distorted. Guess I found my leak.

    Attached Files:

  2. glider

    glider Veteran Member

    Judging from the picture it sure looks like that was the problem.:D
  3. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    Wow!! Were the rocker box bolts not tight? Unbelievable that those gaskets could move that much if the boxes were torqued down tight!!

    Like Glider said, looks like you found your culprits!

  4. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

    the lower rocker gaskets are often a problem and were replaced at some stage by a 1 piece metal gasket this metal gasket works a lot better
    looks like you got the gaskets off in almost 1 part i have spent many a fine hour scraping them off
    hopefully the oil will stay in the engine once you get it back together

  5. oh i was real surprised at how loose some of the bolts were when i started taking things a part. i wondered why there weren't other problems. i figure this motor was put together on the Friday before 4th of July weekend, not on a Tues. or Weds. lol
    the gaskets had only adhered in a few places, so they weren't tough to get off.
    well i'll put it back together tonight and see how things are after that.
  6. got the bike back together Fri. night and took it for a ride Sat. no oil leaks now.:small3d026:
  7. hanger49

    hanger49 New Member

    what is the trick to getting off the rear rocker box cover without taking the engine out
  8. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    On my '91 Dyna (FXDB-S), I used a long allen wrench cut down to just the bend plus about 3/16" to be able to get under the frame and still have enough wrench not to wallow out the fastener. It is slow going, but possible. Just take your time. Helps to have the gas tank out of the way though.