bit of a leaky problem!

Discussion in '2-Stroke Engines' started by 2strokepoke, Sep 11, 2011.

  1. 2strokepoke

    2strokepoke Member

    so my friends bike leaks gas out everywhere.. no its not coming out of the filler cap or fuel line.. its coming out of the carb and exhaust. no its not normal build up of oil.. it won't run for petes sake. I'm assuming its not getting spark

    anyone know the fix?

  2. CroMagnum

    CroMagnum Member

    Sounds like the float is stuck. Your buddy needs to pull the float bowl off the carb and figure out why the needle valve won't seal.

    Then, before he puts it back together, he needs to pull the spark plug, turn the bike upside down and crank the motor over a few times to get all the raw fuel drained out of the bottom end.
  3. motorpsycho

    motorpsycho Active Member

    yep, sounds like a stuck float, or stuck needle & seat for sure.
    the float, needle and seat set up in these carbs is not the best design, but it works.
    it only take a TINY peice of crud to make the needle & seat get stuck open.
    the other possibilty is that the float has a hole in it, and it's full of gas.
    this will cause the float to sink, and let the needle & seat stay open all the time allowing gas to flow constantly and flood over into he engine.

    One other possibilty is that the float has gotten wedged sideways in the bowl (this is kind of common).
    if the float is wedged sideways from too much vibration, it will not be able to float to the top & close the needle & seat.
  4. 2strokepoke

    2strokepoke Member

    actually the problem was the killswitch.. i went to unplug it and the male end of the wire was broken.. took it all off and gave it a try and she fired up. the killswitch caused a no start and my friend kept flooding his bike. good thing I suggested he try the wiring before taking the carb off. :)
  5. motorpsycho

    motorpsycho Active Member

    that doesn;t sound like it was the problem.
    the only way to flood one of these engines is for the needle & seat to be stuck open, or if the primer button was stuck down.
    if the male end of the wire was broken, the motor should have started anyway.
    With a broken wire the engine should still start but the kill switch would not kill the engine at that point.
    people run these engines with no kill switch at all, so i don't see how a broken wire would cause the engine not to start.
    AND, if you disconnected the kill switch, that woudl be the same as having a broken wire.
  6. 2strokepoke

    2strokepoke Member

    well.. it doesn't make sense but it does run now and it's not expelling fuel everywhere lol. though it's hard to start and runs rough so he still needs to play with the carb a bit to get it runnin smooth and possibly switch out plugs ( he was sent the wrong one from SBP)
  7. FelipeCobu

    FelipeCobu Member

    If you have a float failure w/ the petcock closed will have aprox. 20cc of fuel inside the engine, but if you have both nedlee and petcock failure it will flood the engine on gasoline.
  8. retromike3

    retromike3 Member

    sinking feeling

    Had similar problem on my bike. The float was OK but the wire that went through the hinge came undone so it did not stop the gas from coming in the carb float chamber. Problem was that I left it in the garage with the gas valve open. I am upstairs and then I start to smell gas.

    I jog down stairs, open the door to the garage and there is gas all over the floor. I do the best to mop it up and then open the outside door and have a fan in the door running for quite a while until I could breathe comfortably. Lucky for me the garage and the house did not explode. As Hormer Simson would say "DOH" Looks like I wound up with more gas on the floor than I burned riding it in the last two days.

    Well I think I got it all put back together correctly now. I still am going to make sure that my gas tank valve is closed before I close up for the night.

  9. motorpsycho

    motorpsycho Active Member

    yes, closing the petcock should be common practice after every ride.
    the stock petcocks can and will allow gas to flow even in the closed position eventually.
    Your best bet is to use an in-line secondary shut off valve as a "just in case" peice of protection, in conjunction with the stock tank petcock.
    Or, if you have one of the carbs with a built in shut off valve, that will keep the stock petcock from flooding the engine when it starts to leak internally and allow gas to flow in the closed or open postion.

    running 2 shut offs seems like overkill, but unless you put better petcock in the tank, it's the cheapest way to correct the problem. an in-line shut off valve(for lawnowers) is about $3.00.
    Last edited: Sep 13, 2011
  10. FelipeCobu

    FelipeCobu Member

    If you already disassembled a stock petcock you will see that any tiny debris that came inside will cause it to leak, always need to use a strain before it.
  11. HeadSmess

    HeadSmess Well-Known Member

    i believe in faith and dont even have a stopcock/tap :)

    so far, so gooood.... :whistling:

    to date, the needles held up well. as for the last carb...

    the bit about TURNING THE ENGINE UPSIDE DOWN to clear the bottom end when flooded that cromagnon said is very important....

    else the crank seals get popped :eek:
  12. blue 48

    blue 48 Member

    AHHHHH gotta love these engines and there little issues
  13. determined

    determined Member

    This is really good info. I too am fighting the never ending leaks