Fuel Leaking from Carburetor

Discussion in '2-Stroke Engines' started by ariel, Aug 9, 2009.

  1. ariel

    ariel New Member

    Hi, I'm new at motorized bikes. I just installed my first 66cc chinese engine kit from ebay and I ran it yesterday. It ran well but today I noticed fuel leaking from what I think is where the carb mounts to the motor. What can I do to prevent this from happening? I have the fuel valve closed. Please help.

  2. biken stins

    biken stins Member

    If it is leaking with valve closed could be valve pluged with dirt/rust from tank.Drain it ,clean it.
    Check your float to see if it has fuel in it or if it is adjusted wrong.Replace float.Adjust carb..
    clean inside carb .
    good luck.
  3. graucho

    graucho Active Member

    If you try to adjust the float here's a photo to help which way. Remember, only bend prongs SLIGHTLY.

    Im guessing your needle isnt seating itself shutting off the fuel flow. Spray carb cleaner up in the needle area also while you have it apart.

    Attached Files:

  4. ariel

    ariel New Member

    Thanks everyone for your comments. I think my issue was that the carburetor had too much fuel in it causing it to leak. I drained the fuel from the carb bowl and now its not leaking any longer. Thanks again.
  5. EnFlaMEd

    EnFlaMEd Member

    Mine leaks whenever I leave the taps opened. It will form a reasonable puddle on the ground if left over night. I have no idea where it even leaks from. Seems to just pour out of everywhere ie the tickler, drain screw, bowl gasket....no where able to pin pointed.
  6. ariel

    ariel New Member

    Mine was leaking and what I did was this:
    1) Closed the fuel valve
    2) Unscrew the screw that's on the bottom of the carb to drain all the fuel within the bowl
    3) Tightened the screw that's holding the carb to the engine

    I haven't had a problem since.

    Make sure that the fuel valve is closed after every use. Don't let the bike sit over night with the valve open. That's my suggestion.
  7. h0tr0d

    h0tr0d Member

    Quick tip: turn the gas petcock off and run the motor until it starves if you plan on putting it up for a while.
  8. Al.Fisherman

    Al.Fisherman Active Member


    When I get about 1,500' to 1,000' from the house I close off my fuel at the tank.
  9. Bryan Smith

    Bryan Smith Member

    Al. Fisherman has the best answer to me. Turn off the fuel and run it till it dies before you put it away.
    I turn off the fuel anytime I turn off the bike. You will have some fuel/oil dripping from your muffler during break in until you lean the fuel mixture after a few tanks of gas. I still sometimes get a drip or two now and then...It seems to be the nature of these bikes.
    I just keep a piece of paper towel under the engine when parked in the garage.
  10. EnFlaMEd

    EnFlaMEd Member

    How do you stop it leaking while the engine is running though? Mine is not leaking as bad as it was since I siliconed the carb to mani joint but it does still leak. I tried draining the bowl after my last trip but the bike was a pain in the arse to start again. I think I flooded it with the tickler. If I dont drain the fuel I can start the bike without even being on it with just a kick of the pedal (shift kit pedal start).
  11. GearNut

    GearNut Active Member

    That sounds like your float is set too high. Bend the 2 arms that the float pushes against *slightly* down to lower the fuel level in the float bowl.
    A little bit of bend is usually all it takes.
  12. EnFlaMEd

    EnFlaMEd Member

    Might have to give that shot gearnut. Since the silicone job it isnt as bad as it was but that said Ive only done 40kms on it since. The weather here has been nothing but wind and rain for a fair while so I havent had much of a chance to take it on a decent ride. Cheers for the tip.
  13. Bryan Smith

    Bryan Smith Member

    Make sure your float isn't taking in fuel and sinking. You might check it the next time you have the bowl off.
  14. dudeimarobot

    dudeimarobot Member

    Well hey guys... I am having a similar problem as we speak. Got on the bike to ride to work, made it about half a block before the motor bogged down and cut off. Looked down and saw fuel steadily dripping out of the air filter box. Got off, cursed and pushed it back to the house to take the car in to work.

    Just got home and took the carby off... It appears the float has taken in gas, its about 3/4 of the way full! I assume its suposed to be compeletly empty. Seems like the seams slowly let gas seep in. Sucky. ive been squeezing it, trying to drain it all out. Thinking if I can get it all out, clean it throughly... I should be able to wipe a thin layer of expoy around the seam.... Are you speaking from experience Bryan?
  15. Bryan Smith

    Bryan Smith Member

    No experience with that one yet... (knocking on wood). I've just read of those around the forums who've had it happen to them.

    From personal experience:
    I'd spray the float first with a little brake cleaner to remove the oily fuel and scuff it a bit to give the epoxy something to grab on to. If my memory is correct, Epoxy holds things together with a mechanical bond not a chemical one. Still, you should probably order a new float to have on hand in case the repair fails.

    If it just has one hole, you might risk welding the plastic back together with a soldering iron and some similar plastic if filler is needed. I did this once on a plastic trash can using a plastic peanut butter lid cut in strips for "welding rod". It takes a steady hand to pull it off.:whistling:
  16. biken stins

    biken stins Member

    At Lowes in the fastener drawers is a plastic bushing that may be able to replace the float. Have not tried it but the sure look a lot a like. I carry a cork wine bottle cap trimed down for unexpected sinking floats. Would like to know if the bushing works.
  17. dudeimarobot

    dudeimarobot Member

    Nice.. Ill have go by Lowes and check it out. I was also considering a wine cork... why not? For temporary use it should be fine? My carb uses a float that looks like a doughnut. So Id have to drill out the center of the cork. Should be pretty easy though!`

    I ended up mixing some jb weld and slathering it on all the way around where the two halves meet. Will sand it down and put it back together in the AM...
  18. Chris Crew

    Chris Crew Member

    leaky carb

    First, Graucho---thanks for the pictures--that's the best job of demystifying the carb float I have seen.

    In addition to messing with the float and all as you try and address a leak, start with the obvious and tighten all of those tiny screws that hold the bowl on and make sure the drain screw has a gasket and is tight---that fixed mine.
  19. Tjlyons

    Tjlyons New Member

    My name is terry i just got my first occ chopper bike done ran great for 3 or 4 days now gas is leaking from the gas tank it looks like it's comming from the mounting studs and gas is leaking from the air intake on the carb can someone help me
  20. Tjlyons

    Tjlyons New Member

    Oh and my throttle cable don't feel like its working right any idea's