« previous next »
Pages: [1]   Go Down

Author Topic: Oil leak from cylinder stud??  (Read 1749 times)

0 Members and 1 Guest are viewing this topic.

Offline sniper1

  • SNIPER1
  • Hot Shot
  • ***
  • Posts: 299
Oil leak from cylinder stud??
« on: October 26, 2014, 06:44:10 PM »
My '75 550 has oil that is bubbling up from the cylinder stud (Number 11 in the picture). Somehow it is getting through the threads of the nut and spills over. Its not a lot of oil, but very annoying. It gets worse the higher I rev the engine and is worse when the engine is hot. I have torqued the head recently and all are in spec. Anyone ever have this problem? or have any thoughts on what to do to correct?
Logged

Offline calj737

  • Really Old Timer ...
  • *******
  • Posts: 21,020
  • I refuse...
Re: Oil leak from cylinder stud??
« Reply #1 on: October 26, 2014, 07:10:38 PM »
IIRC there should be an oring at that location. Has the head been removed recently or studs replaced? If all is stock, then for some reason it has probably failed.
Logged
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: Oil leak from cylinder stud??
« Reply #2 on: October 26, 2014, 07:37:03 PM »
Here's a picture of what's probably happening, not the same stud but you get the idea. The head gasket is leaking compression close to that stud and a little oil bubbles up through the threads.


Logged

Offline sniper1

  • SNIPER1
  • Hot Shot
  • ***
  • Posts: 299
Re: Oil leak from cylinder stud??
« Reply #3 on: October 28, 2014, 11:43:51 AM »
The head has been removed about 3,000 miles ago. I can't remember there being O-rings around the cylinder studs there. I may have to crack it open again to take a look. Boy, I hate doing that.....
Logged

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: Oil leak from cylinder stud??
« Reply #4 on: October 28, 2014, 07:58:51 PM »
There are no O-rings on the studs.
Logged

Offline Duanob

  • Bold Timer
  • Old Timer
  • ******
  • Posts: 4,009
  • Gotcha!
Re: Oil leak from cylinder stud??
« Reply #5 on: October 28, 2014, 08:35:59 PM »
Quote from: bwaller on October 28, 2014, 07:58:51 PM
There are no O-rings on the studs.

No but there is an o-ring between #11 and #10 that could be leaking. Usually it leaks out between the head and the jugs but you never know. Also don't count out that it could be a leaking puck dripping down on top of the stud/nut.
« Last Edit: October 28, 2014, 08:39:21 PM by Duanob »
Logged
"Just because you flush a boatload of money down the toilet, doesn't make the toilet worth more",  My Stepfather the Unknown Poet

1974 CB360T
1976 CB550K2 Resurrected
1976 CB550F2 Barn Find
1979 CX500 VG "HONDA-GUZZI"
2007 Moto Guzzi Breva 750ie
2015 BMW F700GS
Another 1976 CB550K Cafe?

  __o
_- \_<,
(*) /' (*)

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: Oil leak from cylinder stud??
« Reply #6 on: October 29, 2014, 04:14:16 AM »
It'll take a compression leak to show bubbles through the threads.
Logged
Pages: [1]   Go Up
« previous next »