Engine smoking

Discussion in '2-Stroke Engines' started by Sterno666, May 8, 2011.

  1. Sterno666

    Sterno666 New Member

    My 80cc zoom bicycles engine smokes from the head gasket once it warms up. Can I add/make a paper gaskets to sandwich the metal gasket for a better seal? If not, what can I try to do to stop the leak.

  2. adrian101

    adrian101 Member

    I had this problem with my old motor, have you checked to see if the head is tight down correctly and evenly?

    If you have and that doesn't fix the problem try the paper gaskets and some gasket glue/sealant. If you use this method make sure to follow the instructions for "Setting time" because if you don't it will be a waste of time

    Hope that helps, good luck

  3. motorpsycho

    motorpsycho Active Member

    paper gasket material will not hold up under the heat.
    you need to get a new steel or aluminum head gasket (not sure what they're made of), and put some copper rtv sealant on both sides of the gasket before you put it on.
    you only need a thin layer of the copper rtv, just enough to cover the surfaces of the gasket.
  4. DuctTapedGoat

    DuctTapedGoat Active Member

    RTV on a head gasket is really unnecessary, it's not going to last with the heat and metal gaskets. A metal to metal to metal bead at 15 ft/lbs w/grade 8 steel head bolts is plenty.
  5. retromike3

    retromike3 Member

    head gasket and torc

    On my little engine I only torc my head bolts to 12 foot pounds and it seems to work OK. I need to check the head bolts once a week and they do seem to loosen up after awhile.

    All of the head gaskets I have dealt with are aluminum. I got a thinner one than stock in order to rase the compression a bit, but I am not sure weather it makes any difference.

    I don't know if getting better main bolts will really help but I am sure that it can't hurt. On my first engine the manual said to torc them to 15 pounds and at that level I striped a nut.(cheep boy go slow parts) I thought it was a bolt and replaced what I thought was the offending part only to find out it was the nut.(sheepish grin)

    I have on all of the other hardware have upgraded with the Sick bike part kit and tried to double nut all of my fasteners.

    So far so good and I have about seven hours on my new engine(I installed a tiny tack with the new build) and knock on wood it won't blow up unexpectedly, But who knows. Things usually fail at their weakest point and if you want to keep it prefect don't ever take it out of the box, then in a hundred years it might be seen on the Antique Roadshow. Something I have .serous droughts if you wile be there to get the glory for saving this strange little conveyance that has fortunately slipped in between the the cracks of our legal system.