1984 115 Mercury Problems!

Discussion in 'Bubba's Outboards' started by TOPS, Sep 7, 2007.

  1. TOPS

    TOPS New Member

    Messages:
    4,099
    State:
    Cabot,Arkansas
    The motor is boggin very badley! I am stumped here. I put sea foam in the gas, still no help, I clean all the plugs no help, shot carb cleaner into the carbs no help, Any ideas??
     
  2. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Top those carbs might need cleaning. But first lets try to adjust them. Make sure you have good fresh fuel in the tank. Here is the adjustment procedure and follow it closley as it will take two of you to do this.



    When you are adjusting these things turn the needle in increments of 1/8 th turns and wait a few seconds between turns to let the engine catch up with its self If you have two carbs on this engine then you will adjust each carb individualey. Look on the front of the carb and there should be a plastic screen over the throat of the carb right in the center of the carb top is the needle you need to adjust. When you turn it in to start your setting be sure to just snug the needle when it goes all the way in as not to booger up the fine point on the needle.

    Hope this helps and follow it to the T and read it over real good so you will understand what needs to be done. It will take a long skinny screwdriver to reach it so get one if you don't have one.







    Warm up engine before attempting adjustments.
    This is with the boat in the water. The motor needs to be under a load.

    Start with all idle needles one turn open and adjust for maximum RPM's with with throttle in netural to give about 600-700 RPM's

    With engine idleing at idle speed with engine in forward gear turn low speed mixture adjusting needle counterclock wise until affected cylinder starts to load up or fire unevenly due to over rich mixture.

    Slowly turn needle clockwise until cylinders fires evenly and engine picks up speed.
    Continue clockwise until to lean of a mixture is obtained and engine slows down or misfires.

    Set needle counterclockwise 1/2 to 3/4 turn from lean out position to gain approximate true setting.

    Do not adjust leaner then necessary to attain reasonably smooth idleing
    When in doubt it is better to have a to rich setting then a to lean one.

    If engine hesitates durning acceleration after adjusting mixture idle it is to lean. idle scre should be enriched slightly (counter clockwise ) until the engine accelerates correctly.


    Look on the stop bracket and you should see a screw ( pretty good size ) adjust it so the engine sets there and idles on its on.

    Run the boat out at top speed and that should clean any excess fuel out of it and bring it to a stop and recheck idle speed