Mariner 9.9- 4 stroke has no speed

Discussion in 'Outboards' started by Scott Mckenzie, Apr 4, 2019.

  1. Scott Mckenzie
    Joined: Apr 2019
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    Location: ohio

    Scott Mckenzie New Member

    I have a 1992 Mariner 9.9 4 stroke outboard. It starts right up and idles great. And when i give it gas it runs great. The problem is I can't get any speed out of it. It is currently mounted on a 14' Starcraft V-bottom boat. At full throttle best I can get is around 7 to 8 mph I would think it should do at least twice that speed. And since it seems to run ok I don't know where to start looking for a solution. I'm taking it on a fishing trip out of state and would like to try and solve the problem. Any suggestions?
     
  2. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    There weren’t any 4 strokes in 92.
     
  3. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Leave the engine off.

    Put it in gear.

    Spin the prop.

    It should not turn.
     
  4. Scott Mckenzie
    Joined: Apr 2019
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    Location: ohio

    Scott Mckenzie New Member

    serial number is OH 11654 and below that it says 1992 I just thought that was the year
     
  5. RAraujo
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    RAraujo Senior Member - Naval Architect

    There were 4 strokes in 1992 - I just don't know if Mariner had any...

    I remember some Honda 9.9 4 strokes by late 70's early 80's...
     
  6. ondarvr
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    ondarvr Senior Member

    Yes, but we are talking Mariner, not Honda.
     
  7. fishwics
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    fishwics Quiet member

  8. fallguy
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    fallguy Senior Member

    Had a barebones Lund 14 with an added casting deck.

    A 15 hp motor would barely get it over the hump. It was a rental motor, so I got a brand new 30 and it worked great.

    The motor is either tired or the prop is wrong or slipping, but you are asking a lot of a 10 horse.
     
  9. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    I was thinking much the same, and the load on board the boat might be relevant.
     
  10. Scott Mckenzie
    Joined: Apr 2019
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    Location: ohio

    Scott Mckenzie New Member

    ok I made a mistake in year it says 1997 on serial umber tag. I put it in gear without running and prop will turn clockwise and it kind of clicks and in counter clock wise it does not turn freely it actually turn motor. Is this normal?
     
  11. Blueknarr
    Joined: Aug 2017
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    Location: Colorado

    Blueknarr Senior Member

    Sounds like you broke the shear pin.
    Small outboards have a safety feature that prevents engine damage if the propeller is suddenly stopped. Take the prop off and replace the shear pin. Buy a handful they are usually cheap and often fail. On my Honda it is a simple corner pin
     
  12. baeckmo
    Joined: Jun 2009
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    baeckmo Hydrodynamics

    Nope, that clicking is quite normal; when in fwd gear, the shaft is connected to the pinion via one-way ratchet "cogs".

    Edit. Look at the part no 50 in the picDavid provided in #18; that is the coupling element with its wedge-shaped "cogs".
     
    Last edited: Apr 9, 2019
  13. DCockey
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    DCockey Senior Member

    What is the weight of the boat? What is the weight of the passengers and gear when top speed was 7 to 8 mph? Where were the passenger(s) sitting?

    Do you have experience with higher speed from a engine of similar power in this boat, or are you assuming the top speed should be higher?
     
  14. DCockey
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    Location: Midcoast Maine

    DCockey Senior Member

    Also do you know anything about the propeller on the engine? What was the engine previously used for? What is the "shaft length"?
     

  15. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Your prop is okay.

    Sorry; wish it was an easier answer.
     
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