Engine Trouble bike wont stay running

Discussion in '2-Stroke Engines' started by dennis, Jun 30, 2012.

  1. dennis

    dennis New Member

    what should I be looking at. my bike will ony stay running if choked half way as soon as I open the choke all the way the bike dies.

  2. Greg58

    Greg58 Member

    Sounds like a fuel flow problem, check for a good flow out of the tank. Iff you can give as much info as possible about your engine type and if its new or how many miles are on it you will get more replies.
  3. V 35

    V 35 Member

    New tanks often have slag, and other debris, use a fuel filter, and some clear fuel line 1/4 " Tygon, and 3/16" clamps work well . Your needle jet could be way off, or you might have an air leak. Squirt water
    around carb, and manifold, with engine running. If engine speeds up, you found leak.
  4. jaguar

    jaguar Well-Known Member

    Check the float level to make sure it isn't too low. But usually this problem indicates and air leak, usually where the carb connects to the intake manifold.

  5. dennis

    dennis New Member

    thanks will check all that is mentioned I have a grubie 48/60 cc with aprox 3000+ miles have never had to replace any of the gaskets. have spares from previouse motor kits. have had to do float adjustment once will go throuh all and repot back with the good news.. thanks .
  6. motorpsycho

    motorpsycho Active Member

    first of all, water will not cause the engine to speed up if you have an air leak.
    if anything, it will cause it to bog down or even kill the engine.
    you need to use starting fluid to check for an air leak.
    spray a tiny bit arounf the intake tube - cylinder gasket.
    if the engine speeds up, you found your air leak.
    starting fluid will work MUCH better than water to find an air leak.
    blown intake gaskets are very common on these engines because they are basiclaly made of cardboard & they won't last very long.
    if you have to keep the choke 1/2 way closed to make it run, chances are, you have an air leak.
    the reason it doies when you open the choke is because it's getting way too much air & causing it to run way too lean.

    fuel flow or a clogged fuel filter will have very little to do with the problem you are describing.
    if you have a fuel flow problem the engine will run and eventually die on it;s own because the carb will run out of fuel before the float bowl can be re-filled.
    slow fuel delivery (plugged filter, or a blockage in the tank) will not have anything to do with having to have the choke 1/2 way closed to make it run.
    however, if you have slow fuel delivery, the engine rpms will speed up as the float bowl runs out of gas because the mixture leans out rihgt before the engine stops running.