How to: Replace Main Jet?

Discussion in 'Whizzer Motorized Bicycles' started by go-rebels, Feb 28, 2009.

  1. go-rebels

    go-rebels Member

    Without making a big mess or damaging anything.

    Thanks in advance.

  2. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi go-rebels,
    Drain the gas from the carburetor [ a small screw at the near the bottom of the float bowl], remove carburetor from cylinder. Remove phillips screws that hold the bowl onto the carburetor. The main jet is in the center, remove and replace. If the o-ring gets wet with gasoline you will need to shrink it before you can re-install the bowl. Put in sun or use a hair dryer to shrink o-ring. Re-install the bowl with the phillips screws. Attach the carburetor to cylinder. Done.

    Have fun,
  3. go-rebels

    go-rebels Member

    Thanks again!
  4. go-rebels

    go-rebels Member

    Do you really need to remove the carb from the cylinder or is that for the convenience to work on it on a bench?
  5. RdKryton

    RdKryton Active Member

    It is not necessary but it is very difficult to remove the screws that hold the float bowl in place if you don't remove the carb. Just unscrew the top off the carb slide and pull the slide out of the carb. Let the slide hang on the throttle cable. Remove the fuel line then remove the two 10mm nuts and slide the carb off the studs. From that point it is very easy. Good luck.

  6. Hal the Elder

    Hal the Elder Member

    Reassembling My 22mm Carb:

    I replaced my #90 main jet today with the #82 that Quenton sent me along with my milled head.

    I don't know if I attached the inlet valve correctly to the float lever which moves the valve in and out of its seat. It can slip on that little brass tab either way...does it make a difference?

  7. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Hal,

    It doesn't make any difference which way the valve is attached to the tab on the float.

    Have fun,
  8. Hal the Elder

    Hal the Elder Member

    Thanks, Q...your check is on the way!