Huasheng 31cc Misfiring

Discussion in '4-Stroke Engines' started by roughrider504, Jun 12, 2011.

  1. roughrider504

    roughrider504 Member

    My Huasheng 31cc was tipped over [carb. facing the ground] for about an hour while I was installing a Staton top-mount tank kit. :dunce: Ever since then, it hasn't ran.

    It'll fire up and stumble along if I hold WOT, but that's it. I figured some oil had drained into the carburetor, so I disassembled it and let it soak overnight in the parts washer. After re-assembly, it ran exactly the same.

    I checked the muffler for clogs and pulled the valve cover and the valves are working as they should.

    I still suspect the carburetor is clogged somewhere, does anybody know how to correctly clean out the diaphragm carburetor?

  2. HeadSmess

    HeadSmess Well-Known Member

    didnt happen to pull the plug? before turning it over?

    does it blow smoke ?

    uh oh...
  3. roughrider504

    roughrider504 Member

    The plug color was fine and has been fine since a NGK replacement plug. It doesn't smoke.

    Now there is gasoline dripping from the air intake after sitting for a while. Does anybody know how to correctly clean these carbs?
  4. HeadSmess

    HeadSmess Well-Known Member

    yup. simple. phillips head screwdriver. pull it apart. dont worry, nothing will spring out and get lost when you split it. (but still, be careful) it can ONLY go back together one way. you will find under one diaphgram a little lever affair with the needle valve, held in by one screw. careful here, cus that spring WILL pop out :) also, note which way up this one goes. it can go either way... :(
    that will prob be the problem. some gunk there. under the needle.

    wash it all out in petrol, give it a good blow through with compressed air, reassemble. after having stared at it for an hour or two trying to figure out exactly how it works... :jester:
  5. roughrider504

    roughrider504 Member

    Thanks HeadSmess, I had it apart but didn't notice how to pull out the needle valve. I'll give it a shot.

    Also, I had swapped the original dried up fuel lines with whatever I had lying around, could a larger than stock fuel line cause these problems?
  6. roughrider504

    roughrider504 Member

    The replacement fuel line being too large must be the problem. I lightly pinched the fuel line while starting the engine and it ran and even wanted to idle.

    I guess they have a bunch of different sized fuel lines for a reason. :rolleyes7:
  7. HeadSmess

    HeadSmess Well-Known Member

    no, the line wont affect the carbie and its needle valve. what it might not do is fit on the nipple properly, and the leaks there...

    the needle valve cuts off fuel regardless of the size line used.

    what can be an isuue is the height of tank. if its too high then the pressure of fuel just forces the needle open...

    either way it sounds rich. way too rich.

    so either its pump is too effective, the needles not sealing, or the jets just too big.

    if it has a H and an L needle, try turning em in a 1/4 turn at a time. though i think they use a barrell carb, which is unadjustable(or the ones ive seen have been)