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Results 1 to 6 of 6
  1. #1

    Default oil leaking from cap

    I have a 2003 Mercury 125 HP. I am docking this year at a boat club and have been storing with the motor tilted all the way to have lower unit out of the water. The other day I was walking down the dock and noticed a oil slick behind my boat. To make a long story short I figured out that the oil is leaking out from the oil tank cap. I checked it out closely and the O ring seems to be fine. The cap is marked to turn to right to close and to left to open. I am not sure why as I can pull the cap off when it is turned all the way to the right. I can see in the throat of the tank what looks to be sort of a thread, but I see nothing on the cap that would go into that thread.

    Could I possibly have the wrong cap on this motor? The cap is yellow, with an O ring about half way up on its base and again I see nothing on the cap that would benefit me by locking it in place by turning it.

  2. #2
    Join Date
    May 2013
    Location
    TX.
    Posts
    264

    Default Re: oil leaking from cap

    Could be. Best thing to do is just fill your tank 2/3 full. At full tilt it will just reach the top of the neck. But the oring may look good but not be and the lid may have been jammed buy the PO. I had the same problem and a new lid/gasket kit solved the problem but I still only fill 2/3 full and carry a can of oil just in case.

    Mark

  3. #3

    Default Re: oil leaking from cap

    Quote Originally Posted by Texasmark View Post
    Could be. Best thing to do is just fill your tank 2/3 full. At full tilt it will just reach the top of the neck. But the oring may look good but not be and the lid may have been jammed buy the PO. I had the same problem and a new lid/gasket kit solved the problem but I still only fill 2/3 full and carry a can of oil just in case.

    Mark
    I ordered a new cap and O ring, hopefully that will solve my problem?

  4. #4
    Join Date
    Aug 2006
    Location
    SW Ohio, USA
    Posts
    10,302

    Default Re: oil leaking from cap

    Mine leaked a year ago. The "O" ring looked good. I replaced the ring and it stopped leaking. Got it at a high volume autoparts center; not a chain store. Cost me $.50.
    Fix minor things (replace wear items for preventative maintenance.) that cause major problems before they break.

  5. #5

    Default Re: oil leaking from cap

    Update: After getting the new cap assembly I now know what was wrong. My old cap was not squeezing itself together forcing the O ring out to make a seal when I turned it. The new one works perfectly and I can now tilt all the way up even with the oil reservoir filled.

  6. #6
    Join Date
    May 2013
    Location
    TX.
    Posts
    264

    Default Re: oil leaking from cap

    Great

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