oil from prop hub and the lower unit is this bad?

Discussion in 'Outboards' started by Flying Flivver, Apr 15, 2012.

  1. Flying Flivver
    Joined: Oct 2011
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    Location: Ottawa ON canada

    Flying Flivver Junior Member

    I just got a 1998 johnson 2 stroke and there is oil coming from between the prop hub and the lower unit . Do i have a problem?
     
  2. fast company
    Joined: Mar 2012
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    Location: united states

    fast company Junior Member

    Yes you will need to replace the prop shaft seal.
     
  3. Flying Flivver
    Joined: Oct 2011
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    Location: Ottawa ON canada

    Flying Flivver Junior Member

    thanks for the reply
     
  4. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Not so quick, IMO ! It is normal for a little 2-stroke oil to drip out of there after running, the exhaust passes through there obviously. Check the oil in the gearcase ( after standing for a while) for water ingress, if it is black or dark coloured rather than creamy, water is not entering. Ideally the gearcase should be pressure tested according to manufacturer's specs, there are several avenues for leakage of oil. The bore of the gearcase can become corroded though, and allow oil past the O-ring seal, which I have experienced, but repaired by aluminium filled epoxy and using a slightly thicker O-ring, but that is a "bodgie" fix. Remove the prop and pressure test (via the top oil fill hole) and you'll quickly see any oil leak.
     
  5. Flying Flivver
    Joined: Oct 2011
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    Flying Flivver Junior Member

    thanks Mr Efficiency for the diagnostic info the oil was black but it only ran with muffs on a stand recently
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    It may not be time to assume panic stations. I recall pressure testing a leaky gearcase by attaching a hose to the top oil fill hole, making sure the seal was good, and using just a fuel primer bulb to push some air in. Sure enough oil started to seep out from a point on the inside bore/bearing carrier joint, not the shaft seal. If you run with the muffs on and see some oily gunk running out after you stop it is likely unburnt two-stroke oil, more so if it was running at idle for any length of time. Black oil sounds good to me.
     

  7. Flying Flivver
    Joined: Oct 2011
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    Location: Ottawa ON canada

    Flying Flivver Junior Member

    thanks after i run it in water a few times i will check the lower unit for some creamy oil.
     
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