Merc 115 Carb Adjustment

Discussion in 'Bubba's Outboards' started by dominoman, Jun 6, 2008.

  1. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    On the 1983 115 Tower of Power Merc, just finished the carb rebuild. It ain't no wonder it wasn't running right. The Seloc manual does not suggest a starting point for the carb adjustment. Before I have always started 1 1/4 turns out from a light seated needle. Open to any advice. By tomorrow morning the new tach will be installed along with new fuel tanks, lines, bulb, water separator/filter. I do have a test tank that I can run the engine in if that's any help.
     
  2. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    OK now I need help. Got the carbs back on, engine fire and runs, problem is the bottom carb is pouring fuel out of the overflow. Checked the new float, seems fine. I am at a loss.
     

  3. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    A small copper crush washer, under the seat?
     
  4. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    New washers under each seat, only other thought was that it could be a bad float, they were brand new, guess it could be bad.
     
  5. zappaf19

    zappaf19 New Member

    Messages:
    1,574
    State:
    Monticello,IN
    My middle carb did the same to me after I redid the carbs. I ended up taking them off again and took them to a mech to have them set. I can take those off blind folded now. LOL
    Bill
     
  6. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    I am beginning to suspect that the floats are not the correct ones. Looking at them side by side they appear to be different.
     

    Attached Files:

  7. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Take it back off. Take the bowl off and hold the carb body upside down, so the float and needle is seated. attach a fuel line to it and prime the carb. Notice what happens.
     
  8. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    Maybe I'm missing something, the bowl is made onto the carb, it just has a top that comes off.
     
  9. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    Here's a photo of what the carbs look like
     

    Attached Files:

  10. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    The heigth of the float including the spring is what you are looking for here.
    Those springs are pre set at the factory and you don't want to bother the spring. You can adjust the float rise at the needle. I'll see if I can find my blow up of that carb and see if I can offer anything that will help but bob paul is on the right track here.
     
  11. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    OK went back, checked all I had done, is the needle seat suppose to be screwed in all the way or is this where adjustments can be made? I can get one carb to stop squirting fuel and then another one starts. 'Bout to pull out what little hair I got left. Besides the fuel leak, the motor starts like a dream, runs pretty smooth.
     
  12. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    Big ol' Dodge truck cured the carb problem, drug it to the shop.
     
  13. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    Good news yesterday, got the boat back from the shop, was the float adjustment that was needed. While they had it got them to run diagnostics on it, has almost identical compression on all cylinders, fine blue spark, timing checked fine. Mechanic says the motor does not look like it has many hours on it at all. Had a de-carbon done along with all checking. It's reloaded with everything but the rods, just waiting for the wind to die down, it's going to the water somewhere this weekend.
     
  14. dominoman

    dominoman New Member

    Messages:
    445
    State:
    Dale, Texa
    Got a chance to hit the water this weekend, boat runs great, too bad the fish weren't cooperating. Did have a chance to work with the new HB 797 SI, it is awesome.