99 1100GS oil sight glass blew out.

Discussion in 'GS Boxers' started by Bender, Oct 2, 2012.

  1. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    And that was the winning ticket.

    I taped the old one to the new one, used the same socket as last time. A film of oil and the thing damn-near installed itself.

    I am wondering now if the first replacement was perhaps too big? It would not go into the hole.
    #21
  2. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    First time I hit the freeway, this one blew out. I had the third one with me and installed it with a tent peg and a tire iron. I took the o-ring of the oil filler cap and limped home.

    Where is the crankcase vent for this thing? I'm thinking maybe its pinched or clogged.
    #22
  3. Tosh Togo

    Tosh Togo Long timer

    Joined:
    Nov 21, 2010
    Oddometer:
    1,594
    :thumb :thumb

    Someone finally saw beyond the symptoms... :clap

    To the OP: you need to find out WHY the cases pressurized enough to force the old sightglass out of its' hole. Simply putting a new one in doesn't cure the underlying cause, and it wlll happen again. :cry

    Fwiw, I've got a 30 year-old aircooled bike with well over 100K on it, and the OEM sightglass is still happily in place. I've known of several others like it whose owners neglected the breather system, and the sightglasses always went walkabout soon after. :deal
    #23
  4. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    It's my understanding that the stock plastic sight glass will just get so brittle they eventually just let loose without over-pressurizing the crankcase. That is what I thought happened the first time.
    #24
  5. JimVonBaden

    JimVonBaden "Cool" Aid!

    Joined:
    Feb 11, 2005
    Oddometer:
    64,826
    Location:
    Alexandria, VA
    It can for sure. If the second one went in that easily it was likely wrong, defective.

    How hard was the third one?

    As for the crank case vent, top left side of the motor, under the ABS unit forward of the Bowden Box. Sometimes they git pinched, or there is an obstruction in the air cleaner. Also drain your air cleaner to see if there is oil in it.

    Jim :brow
    #25
  6. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    The third one went in along side the road. Something I said couldn't be done based on the first one I had.

    So how would I know a good one from a bad one?
    #26
  7. sdpc2

    sdpc2 Just another Rally Rat

    Joined:
    Oct 10, 2003
    Oddometer:
    1,235
    Location:
    Charlotte, NC
    box?
    #27
  8. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    I believe there a little squeezie nipple on the bottom of the Airbox that will allow you to drain oil and/or water from it.
    #28
  9. JimVonBaden

    JimVonBaden "Cool" Aid!

    Joined:
    Feb 11, 2005
    Oddometer:
    64,826
    Location:
    Alexandria, VA
    It is actually a knob on the bottom left side of the airbox towards the rear of the bike at the back of the airbox. It is accessable above the left footpeg. Just turn it about 1/4 turn and it comes off.

    Jim :brow
    #29
  10. vintagerider

    vintagerider Long timer

    Joined:
    Nov 20, 2005
    Oddometer:
    1,976
    Location:
    the west
    The oil cover is a twist lock. From side stand side cover the exhaust. The drain cover is on the underside of the air box, to the rear, LS. It it hasn't been off before it may be very tight. It has an o-ring. Install clean and dry. Spray the exhaust with brake cleaner if any oil drained on it. Lift the tab on the oil filler lid on the L rocker cover. Remove the oil fil base part and clean the o-ring, install dry.

    Parts price break is 10 quantity for some dealers.

    corrected
    The crankcase vent hose can be found on the RS just above the telelever pivot. The actual rotary crankcase vent is in the engine. The 1150 can sometimes be blocked by a mis-installed rear main seal but that should not be a problem on the 1100.
    #30
  11. JimVonBaden

    JimVonBaden "Cool" Aid!

    Joined:
    Feb 11, 2005
    Oddometer:
    64,826
    Location:
    Alexandria, VA
    Correct, not top left, top right side access to the vent tube.

    [​IMG]

    Air cleaner, air box, same thing effectively.

    [​IMG]
    bottom right.

    Jim :brow
    #31
  12. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    Didn't have a lot of time to mess with it today. But I did pull the plug out of the airbox and got a couple drops of oil. Unusual?
    #32
  13. JimVonBaden

    JimVonBaden "Cool" Aid!

    Joined:
    Feb 11, 2005
    Oddometer:
    64,826
    Location:
    Alexandria, VA
    Nope, a couple drops is normal.

    Jim :brow
    #33
  14. Pekkavee

    Pekkavee Been here awhile

    Joined:
    Oct 22, 2006
    Oddometer:
    346
    Location:
    Finland
    Nice tip-. Thanks.
    Pekka
    :eek1:eek1:eek1
    #34
  15. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    Ok, I believe that PVC hose comes out of the crankcase just aboput the tele-lever pivot point? If so, I found it. The PVC hose was supple and still rubber-like. Not hard and cracking.

    Took the seat off and nosed around a bit. Checked the air cleaner and found no traces of oil on it, but there is a thin film of oil underneath it on the bottom of the airbox. This leads me to believe that I am not fighting a worn-out engine. I kinda think that if it was compression getting past the rings that there would be oil all over the airbox. Correct?

    I am seriously not wanting to start tearing into this thing to get the airbox off to check that PVC hose, so I am thinking that maybe I can rig up an adaptor to run about 15psi of compressed air into the oil filler hole to see if it holds pressure, or if it flows as it should.

    How bad is that last idea? Will I screw something else up if I try this? And if it vents this pressure, what else do I need to check?
    #35
  16. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    Really?
    #36
  17. slartidbartfast

    slartidbartfast Love those blue pipes

    Joined:
    Dec 23, 2003
    Oddometer:
    5,933
    Location:
    Southern Louisiana or Southern England or ...
    I wouldn't use 15psi. Better might be to blow gently into the breather hose from the airbox end. I'd do a leakdown test on the cylinders too.
    #37
  18. AndyCap

    AndyCap Mineral Oil Anyone?

    Joined:
    Mar 4, 2009
    Oddometer:
    1,487
    Location:
    "The Mack", New Hampshire
    #38
  19. Bender

    Bender I can pass this guy..

    Joined:
    Feb 15, 2005
    Oddometer:
    41,137
    Location:
    Cypress, Texas.
    I have got the replacement thing down pat.

    I am trying to figure out why I have popped two oil sight glasses out in a matter of about 5 miles.
    #39
  20. JimVonBaden

    JimVonBaden "Cool" Aid!

    Joined:
    Feb 11, 2005
    Oddometer:
    64,826
    Location:
    Alexandria, VA
    I highly doubt you have excessive crankcase pressure. If you did you would have leaking seals all over the place. I suspect wither you have gotten a bad sight glass, or your sight glass hole is somehow out of spec.

    What I would suggest is that you install a new one, drille some safety wire holes around it, and safety wire it in. This has been done successfully before.

    Jim :brow
    #40