R90 - 2 oil leak questions

Discussion in 'Airheads' started by pkboxer, Oct 5, 2012.

  1. pkboxer

    pkboxer Been here awhile

    Joined:
    Jun 15, 2011
    Oddometer:
    107
    Location:
    cincinnatus oh
    I have 2 spots where I'm getting a "misting" of oil after longer rides.

    Did two 175 mile days last week and 220 miles yesterday and get this...

    First pic....

    [​IMG]

    Oil on the shelf but it's actually more wet at the oil gallery plug and down below that, at the oil pan.

    You can see a little "peninsula" of dry area on the shelf, so it looks to be blowing over from the left side and not coming straight back.



    Second pic...

    [​IMG]

    Light mist on the little "cap" on the carb (painted black, that's not all oil) and then a small amount of oil in the boss where the throttle cable rest????

    Ideas
    #1
  2. Bill Harris

    Bill Harris Confirmed Curmudgeon

    Joined:
    Sep 20, 2008
    Oddometer:
    9,746
    Location:
    backwoods Alabama
    First leak: see that slotted thingamabob on the left center? That is a plug to a main oil gallery. It frequently weeps. Sometimes seeps. Rarely leaks. Invariably hard to get at to stop the weeping or seeping. Snugging it might work, but the final solution is to remove it (there'll be oil oozing outta the oil gallery), clean the internal threads off with brake/carb cleaner and install with Red Loctite or (better) Loctite Thread Sealant.

    Second leak: Ain't hardly. That's the Patina of Loving Use. OTOH, if someone lubed the throttle cables, that might be residual oozage. Don't lube the throttle cables-- they are teflon-lined and don't need it.

    Go ride...
    #2
  3. pkboxer

    pkboxer Been here awhile

    Joined:
    Jun 15, 2011
    Oddometer:
    107
    Location:
    cincinnatus oh
    Yeah, I was suspecting that plug. Does it come out without removing the engine?

    Or would green locktight work into the threads after a cleaning?


    The carb one got me since there isn't really oil anywhere else on the thing,

    I put the cables on and didn't lub them ever unless it's grease "drippings" coming all the way from the throttle end.:ear
    #3
  4. disston

    disston ShadeTreeExpert

    Joined:
    Mar 22, 2011
    Oddometer:
    12,368
    Location:
    Silver Spring, Md
    The one for the carb top looks like the steel insert, round disk, crimped into the carb top has worked it's way to loose. Common problem. Various ways to seal them. I've even heard of somebody who re-crimped the top, hardly seems worth it. Some riders put some Silicone Sealant in the seam between the disk and the Aluminum. I used Epoxy and added a BMW roundel that some dealers sell that's the right size for this spot. That size roundel is not an OEM part but it is available. Some riders use a coin for the carb top or some other round object that's really only there to hide the epoxy.

    After sealing, if this is really the problem, the carbs will work better and you may have to retune.
    #4
  5. supershaft

    supershaft because I can

    Joined:
    Sep 9, 2010
    Oddometer:
    9,116
    Location:
    San Francisco Bay area
    I get those plugs to not even weep using liquid thread tape. The trick is getting the threads clean. It takes a while for the oil to drain out. It is important to re-prime your oil pump IMO! Good luck!
    #5