Carburetor is leaking gas out of overflow tube... I need help.

Discussion in '2-Stroke Engines' started by trupro, Jul 26, 2009.

  1. trupro

    trupro New Member


    I cant post in the 2 stroke forum yet. So I will try here for now.
    Here is my problem.

    I bought a new engine off ebay. It is a slant head with the carburater that is mounted closer to the engine. (closer than the last engine I had)

    But anyways,
    I built the bike. I did put a fuel filter on it in line.
    I also (before I started the engine for the first time)
    Put a lid-full of 2 stroke oil in the hole where the spark plug goes.

    (This was suggested in the operating manual online for "spooky sprocket" company.)

    So, the bike will run (fairly well) for about 1 minute. Then it will stall.
    It stalls ( I think) because I have the carburator gas flow button turned horizontally. But If I turne it vertically, gas steadily comes out of the tube.

    I have tried to look at the the needle and the spring. But I dont know what to look for.

    I also was going to take the carburator off. But one of the two nuts holding the carburator onto the engine is mounted flush to the air breather.

    So there is no way I can get any tool around the edge of the nut to grip it out.

    I really dont want to have to order another carb, since this is brand new.

    Let me know if you can help me. I would be greatly appreciated!


    the bike will run for about one minute... then it will idle real high for 2 seconds.. then it dies.

    This first run today, it ran for a good 5 or 10 minutes without stalling.

    Thanks for the help!


    DJEEPER Member

    float stuck?
  3. trupro

    trupro New Member

    i got the carb off finally.
    Starting to look at everything.

    What am I looking for?
  4. QuadManiac

    QuadManiac Member

    Inside the bowl on the bottom (held on by screws) there is a float pushing up on a small valve. That valve is not closing off the flow of fuel. Either the mating surfaces between the valve and it's seat are scored or corroded, or there is some piece of debris preventing the full closure. Look at both the valve and the seat carefully and I expect you will see something abnormal - not smooth and continuous.
  5. biken stins

    biken stins Member

    When mine did what your is doing it was the float. Some how it filled with fuel and would not stop flowing untill fuel was turned off. Replace it.
    Or take it out and put a cork in bowl and see if it stops.
    Float has been sitting a while and fuel is still in it. Shook it well but nothing comes out. Must be a real small hole.
    The cork trick was found om this site and does work well and long enough to get another.
  6. trupro

    trupro New Member

    Thanks for the help.
    It was the float.

    A little carb spray into the mechanisms as I worked them gently back and forth seemed to do the trick.. I have NO gas leak now.

    Thank you for the replies!
  7. graucho

    graucho Active Member

    Glad you got it fixed. Here's a shot for future reference if you have problems.

    Attached Files:

  8. Hawk

    Hawk Member

    Hi Graucho,
    I followed your procedure and I made it worse LOL! The minute I open the fuel valve the carb bowl fills up and starts come out the top.....primer and air filter as near as I can tell. This is a factory 66cc 2 stroke carb..NT. Any other thoughts? Buy a new one? If so which one?
    Tx Jim
    Indian Wells CA

    DJEEPER Member

    you did it wrong...
  10. Molotov256

    Molotov256 Member

    Haven't tried the cork thing, but I'd been having similar issues and never once thought to check the buoyancy of the float. Sure enough, I read this post, went out to the garage and pulled the bowl off the carb, and the float was 50% full of gas. I've adjusted the metal piece above the float at least 5 times on this %!$@ing carb, and now I understand why it wasn't helping.

  11. take off float,empty it ,then seal it hard can it be- its only plastic and is only a small hole to seal.
  12. Hawk

    Hawk Member

    DJEEPER ( and Groucho),
    You were right --a couple more tries and I fixed it. I was bending the wrong prongs. I needed to bend the 2 small ones to hold the pin tighter in the seat. But I did bent the larger ones, that helped the float to put more presure on the pin. It is shown in Groucho's photo if you look closely.