Fuel Bowl Overflow:

Discussion in 'Whizzer Motorized Bicycles' started by Hal the Elder, Jan 13, 2010.

  1. Hal the Elder

    Hal the Elder Member

    Hey...Happy New Year from Me & Oscar!

    Sometimes when I start Oscar, fuel will start flowing from the fuel bowl overflow tube, and a light rap with a hammer will stop it.

    Does this mean that the float valve is not stopping the flow from the tank every time?

    What's the spec on the float valve adjustment?


  2. If tapping the bowl helps it sounds like the float is a little sticky. Clean the carburetor and make sure the float can pivot up and down smoothly without any catches.
  3. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Hal & Oscar,

    The float setting is 22 MM.

    Also check & clean the float needle & seat.

    I found Gummout carburetor & fuel injection cleaner does wonders on these carburetors. I normally mix much heavier than suggested on the bottle. I normally pour several oz. into a full tank of gas.

    Have fun,
  4. go-rebels

    go-rebels Member

    Also, put in a small in-line fuel filter, else you'll be tapping and cleaning often!
  5. KilroyCD

    KilroyCD Active Member

    I have heard that another thing to help keep the float from sticking is to mix an ounce or so of Marvel Mystery Oil in with your gas.
  6. go-rebels

    go-rebels Member

    I have done exactly that, but the paint chips will still cause you fits! I did not fix my leaking problem until I added the inline filter.
  7. davido

    davido New Member

    First tank leaked; overtight on curved upper bar. New tank had sediment. Engine bogging, overflow gushing. Spark plug cleaned and gapped. Then removed carb, found metallic sediment in bowl, cleaned, added inline filter and presto. Smooth again. Hopefully no cylinder scoring...
    Any way to prevent the float from bouncing too much on bumpy roads? Suspect it's causing the studdering on theses older streets here in Sacto