Bores filling up with fuel

Discussion in 'Outboards' started by valvebounce, Jun 11, 2019.

  1. valvebounce
    Joined: Dec 2010
    Posts: 471
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    Location: manchester uk

    valvebounce Senior Member

    I have just changed the fuel pump on my 1999 25hp outboard.
    It is impossible to pull the engine over with the cord because the cylinders have filled up with fuel.
    Anybody got any ideas?
     
  2. Mr Efficiency
    Joined: Oct 2010
    Posts: 7,343
    Likes: 231, Points: 63, Legacy Rep: 702
    Location: Australia

    Mr Efficiency Senior Member

    I doubt that, V. There must be another problem. The motor is not seized ? Take out the plugs and have a look at them for rust on the electrode. Maybe the recoil start has locked up. Can you get your hand on the flywheel to see if it is free ?
     
  3. valvebounce
    Joined: Dec 2010
    Posts: 471
    Likes: 9, Points: 18, Legacy Rep: 124
    Location: manchester uk

    valvebounce Senior Member

    Gooday Mr E,
    The cylinders are full of fuel.With the plugs out the engine pulls over easily.
    When I turn it over,fuel squirts out of the plug holes.I looked in the plug holes,
    and they were brimming over with fuel.
    If I pump the bulb on the fuel line,it doesn't get completely solid,and it's possible to keep pumping.
    The end result is the fuel being pumped into the cylinders.
    I am wondering if this new pump has been assembled wrong.
     
  4. JamesG123
    Joined: Mar 2015
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    Location: Columbus, GA

    JamesG123 Senior Member

    Carb float valve bad or even missing? It would help if you gave a specific make and model.
     
  5. valvebounce
    Joined: Dec 2010
    Posts: 471
    Likes: 9, Points: 18, Legacy Rep: 124
    Location: manchester uk

    valvebounce Senior Member

    The outboard is a 1999 25hp Johnson-J25RLEEB
    The fuel pump is brand new.I have had the carb off and cleaned it with carb cleaner(removed the jets)
    I reset the float height and checked the float pin and clip.
    I took it for granted the pump would be ok with it being new.
     
  6. JamesG123
    Joined: Mar 2015
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    Location: Columbus, GA

    JamesG123 Senior Member

    Pump seems to be working just fine. lol
     
  7. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    There would be fuel coming out all over if the needle valve wasn't working.
     
  8. Yellowjacket
    Joined: May 2009
    Posts: 562
    Likes: 71, Points: 28, Legacy Rep: 447
    Location: Landlocked...

    Yellowjacket Senior Member

    A couple of things to look at.

    First, when you pump the bulb is it overflowing into the carb??? Typically if the float setting is wrong you will be able to pump hard and it will overflow out the front of the carb or come out of the jets.

    Second, if you have a leak in the fuel pump diaphragm it will leak directly into the crankcase and that can directly fill up the cylinder, usually the one that is used for the fuel pump, but if you pump in a ton of fuel and have a leaking diaphragm you can fill them both up in pretty short order.

    I would look at the carb first and make sure that when you pump the bulb it isn't coming out of the jets. If it isn't, then look at the fuel pump diaphragm. If you want to double check the carb, route the fuel hose to bypass the fuel pump and if it doesn't pump up hard then it's the carb. If it pumps up hard then the diaphragm is leaking.

    More than likely one or the other...
     
    BlueBell likes this.

  9. BlueBell
    Joined: May 2017
    Posts: 647
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    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    Did it run fine after the carb rebuild?
    What other work was done after it last ran fine?
     
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