OMC Stringer 400 problem

Discussion in 'Sterndrives' started by Rich B., Jul 7, 2015.

  1. Rich B.
    Joined: Jul 2015
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    Rich B. New Member

    I recently acquired a 1980 16' runabout boat that has a GM 120 HP 4 cylinder and the OMC Stringer 400. Well the issue that I am having is the out drive will raise enough to break the seal to the intermediate exhaust housing while driving. You know this has happened when you hear the volume of the exhaust get louder and you start loosing RPM's on top end. I have to stop and lower the drive then off I go again. This consistently happens when taking off full throttle i.e. pulling a skier, etc. Is the tilt clutch assembly responsible to hold the out drive in the down position, and only allow upward movement in the event the lower unit hit something in the water while under power? I am wondering if the clutches need replaced or is there an area I should be looking at to fix the issue?
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcome to the forum.

    The first part you need to buy for this boat (there'll be more, trust me) is a repair manual, for the engine/drive combo you have.


    It's probable you need several parts, once you get things accessed, but the obvious one is a new "transom boot seal kit". Parts for this model OMC are starting to get hard to find, simply because OMC hasn't existed for a couple of decades now, but this part is still available.
  3. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Is it a Stringer, a Stinger, or a Stinker ?
  4. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    When you take off, the drive stays in position and there are no loads on the seal.

  5. sdowney717
    Joined: Nov 2010
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    Location: Newport News VA

    sdowney717 Senior Member

    yes, the clutch pack is slipping if the lower gear case is actually rising.
    But why would it lift up, motor prop force is trying to force it down. So this makes no sense to me.
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