Motor Not Right!

Discussion in 'Boats, Blinds, & Gadgets Forum' started by fireduck, Dec 16, 2017.

  1. fireduck

    fireduck Elite Refuge Member

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    My 1999 Mercury 50hp 2 stroke is SILL not running right!! Just had the carbs cleaned ( they were a little dirty) put new plugs in- and still no improvement. Idles OK, but will not open up to full speed. Maybe half speed at the BEST! Just will not break through. Fresh non ethnol fuel in it with some sea foam. AND ITS DUCK SEASON! Any ideas or information would be greatly appreciated!! THANKS-fireduck (Kenny)
     
  2. bruce

    bruce Elite Refuge Member

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    Check spark, check compression, and check gear oil just to be sure you d on't waste time on an engine that has other problems. About half speed would often mean loss of a cylinder. Spark plug could be the problem.
     
  3. Timber Hole

    Timber Hole Senior Refuge Member

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    Sounds like it's not getting air. Any chance the mud daubers got to it? Also wonder if the fuel pump isn't putting out?
     
  4. Clayton

    Clayton Moderator Moderator

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    I had something similiar happen and it turns out it was the fuel line.
     
  5. fireduck

    fireduck Elite Refuge Member

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    It will kick in sometimes- then it boggs down again. I've had the motor for about 6 years and its self mix with quick silver. Maybe change to Mercury oil? Problems-Problems! fireduck
     
  6. bruce

    bruce Elite Refuge Member

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    A sharp on-off hesitation is usually electrical. A slow bog -down is usually fuel. I missed where you said that you had changed the spark plugs. my guess would be that an electrical component is the problem. Communication is always a problem on the Internet. Is there a reason for not just taking it to a qualified dealer?
     
  7. Phytoplankton

    Phytoplankton Elite Refuge Member

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    Sounds like it could be a coil issue. When they start to break down they often short out when the motor is under load. Check and clean all the connections first, look for corrosion and cracked insulation on the wires. When you changed the plugs were any fouled? If so, swap the coil on the fouled plug with another coil and see if the fouled plug changes. Another thing if you have close access to a launch ramp, in the dark, start the engine with the cowling off and try to accelerate while someone watches the coils, you'll often see a spark jumping from the coil to the block if the coil is going bad. I guess it could be a problem with the reeds, but that is much less likely.
     
    duckbuster5901 likes this.
  8. fireduck

    fireduck Elite Refuge Member

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    Just spoke to a Boat Motor Repair shop that works on Mercury motors. He said it could still be the carbs. He said carbs need a DEEP CLEANING in all holes. He would check it out quickly as possible and get me back on the lake! I did not know about this shop- about 20 miles from home. If this works out - this will be my Go To Place in the future. THANKS for all help and info! I will post back later with results. fireduck Kenny
     
  9. Phytoplankton

    Phytoplankton Elite Refuge Member

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    Sometimes you can clear a clogged jet by doing an "okkie tune-up", get the engine running, advance the speed manually to about 3000-4000 rpms and cover the throat of the carburetor with your hand until the engine dies, sometimes the suction is enough to pull the blockage out of the jet. Worth a try in a pinch.
     
  10. duckbuster5901

    duckbuster5901 Senior Refuge Member

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    Sounds like a stator gone bad to me. Years ago had exact same problem w a 2 stroke 25 merc.
     

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