Loss of power

Discussion in 'Outboards' started by RayD, May 28, 2018.

  1. RayD
    Joined: May 2018
    Posts: 5
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    Location: Florida

    RayD Junior Member

    Has anyone heard of this one? Cruising along the inter coastal nicely and jumped a wake of a boat and came down a little hard. Ended up behind the smooth water then, no power up. Could not get past 2000 rpm. It tried to accelerate a few times when I tried but nope! This has happened three other times with the same reason. Jumping a medium wake to get over. Is something coming stuck or loose? I have a new primer bulb, fuel separator, got a tune up and compression test and each time it happens I try different things. Then go out and it’s fine. But it happens over and over. 90 merc. 2001 on a 17’
     
  2. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Do you have a clear fuel filter where you can see the inside? If not; add it.

    Is it running rough or just won't throttle up?

    My hunch is air is getting into the system somehow.

    You can temporarily run a piece of clear line into the carbs and run hoods off and watch for bubbles.

    Something is loose in the fuel system most likely.
     
  3. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    If you verify no issues with fuel; you would move to electrical.
     
  4. RayD
    Joined: May 2018
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    Location: Florida

    RayD Junior Member

    Doesn’t really run rough. No clear filter but will get one. Thanks for that advice
     
  5. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    Run some clear line at the carb/fuel intake. If you have a loose line off the water sep even; bubbles might be the troubles. Of course make sure your temp lines are tight. Get a coupler so you can just unhook and rehook.

    Another possibility is a failing rev limiter. They can be bypassed. You can goggle it. Not sure why hitting a wake would affect it, but perhaps there is a loose connection there? Internal failure...cools off and then works?
     
  6. RayD
    Joined: May 2018
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    Location: Florida

    RayD Junior Member

    Tried cooling off. Had lunch let it sit. Still no power. Thanks will try your advice.
     
  7. jorgepease
    Joined: Feb 2012
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    Location: Florida

    jorgepease Senior Member

    sounds like a loose ground wire to me
     
  8. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    I would bet its fuel. Electrical isn't so consistent.

    Have you checked the air hole on the tank cap, is it blocked a bit ?
     
  9. RayD
    Joined: May 2018
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    Location: Florida

    RayD Junior Member

    Thank you all. Some things I had not even checked!
     
  10. Barry
    Joined: Mar 2002
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    Barry Senior Member

    Is it a built in tank or portable?

    I would borrow a portable tank and when it happens switch over to the portable to see if it is a fuel flow situation,

    There is a slight chance that if it has a built in anti siphon valve at the top of the fuel tank when jolted, it loosens up some crude and restricts the fuel flow

    When it happens is the primer bulb hard? If not, have someone squeeze the bulb when you cannot make rpm and see if it makes a change. The anti siphon valve is a spring loaded check valve on top
    of most gasoline built in tanks so that if you have a fire and the hose burns through, the fuel will not feed the fire or if a float (on an inboard carbed engine) should jamb open, the fuel will not be siphoned into the engine
    room.

    They are pretty small, and unless you know what you are looking for, can easily get missed. Note if you find it be EXTREMELY careful trying to take it out to clean if it is an older installation, as it is convenient to put only one wrench on the fitting and break the draw fitting. If it were mine, I would apply some Liquid Wrench, (not WD 40) or another dedicated penetrating oil to the fittings over the course of a week, then use 2 FITTING wrenches so you don't strip the ferrule nuts
    and check to see if the anti siphon valve have junk in them, restricting fuel.

    Most draw lines have a rigid pick up tube that has a fine screen on the end. A sudden impact MAY cause the sediment to temporarily clog the draw as well.
     
  11. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Which 2001 Merc?

    Pick up tube and/or anti-siphon valves don't have an immediate effect, it takes a minute or so to run the fuel low enough to exhibit problems, so if it's an immediate response to jumping the wake look closer to the motor.
     

  12. RayD
    Joined: May 2018
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    Location: Florida

    RayD Junior Member


    This is very helpful thank you! And it is a built in tank...
     
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