Engine Trouble ran great for about 30 miles now won't start

Discussion in '2-Stroke Engines' started by hunterhv, May 4, 2014.

  1. hunterhv

    hunterhv New Member

    i bought an 80cc engine kit with high hopes. after many headaches i got it all together. everything seemed to run really nicely for a while (for a new motor a ran it a little to hard). i switched my fuel ratio and thats when everything went south. i had rid through 1 tank of new ratio fuel (about 18:1-20:1, from originally using the sugested 16:1 ) and when i filled it up again, i was riding and every few seconds at full throttle it would loose power for about 2 seconds and then it would come right back but when i got to a hill i started to go down it with a little throttle the motor started to backfire a lot and as the hill started to flatten out i lost power slowly until my bike died. i let it cool down for about 20-30 mins then tried to start it and it did run for about a minute until it lost power then died again. i reapeated that process twice more until i gave up. the next day i switched to the original fuel ratio of 16:1, and as soon as i dropped the clutch the engine started and with out giving any gas it started gaining speed until i pulled in the clutch and it revved up super high, at that point i hit the kill switch and tried again. it did the same thing, but i rode the bike halfway home like that until it died and i could not get it to start again. i have no idea what it could be, please help

  2. butre

    butre Well-Known Member

    Sounds like a stuck slide needle to me. Did you ever do any messing around with the carb?
  3. HeadSmess

    HeadSmess Well-Known Member

    the backfiring, in a fourstroker, atleast, always means ignitions playing up and being intermittent.

    your problem, at first sounds simply like a blocked jet.

    simple. pull bottom of carb and stuff a paintbrush bristle through the tiny hole in the small brass thingy on a tube that you will see. thats the jet.

    chuck it back together, and if its still playing up, start suspecting the ignition. bad earth more than likely.
  4. KCvale

    KCvale Motorized Bicycle Vendor

    Sounds like a fuel problem to me.
    As the float bowl runs empty the engine revs before it dies as air:fuel ratio changes.
    Check the little filter in the petcock going in to the gas tank or better yet remove it and put an inline filter on it.
  5. hunterhv

    hunterhv New Member

    The only thing i have done so far is the first day i got the bike i adjusted the idle so it would still run if i pulled the clutch in
  6. crassius

    crassius Well-Known Member

    this sounds like you may not be mixing fuel in a can that you can shake well "about 18:1-20:1"

    you may have a glob of pure oil in the bottom of your carb

    the reving sounds like the slide or cable is stuck at the carb too

    when you get it running, you might want to go to 32:1 also
  7. hunterhv

    hunterhv New Member

    i ended up finding the problem it was the coil in the magneto that needed a replacement, after that it started right up
  8. HeadSmess

    HeadSmess Well-Known Member

    :willy_nilly: i win i win! :willy_nilly:

    ignition :) just not the right bit of it :(

    *retreats back into cave*
  9. jaguar

    jaguar Well-Known Member

    yeah but the faulty ignition can't cause the high reving. that is from an air leak (bad carb-to-manifold connection, bad crank seals or good seals caught on the shaft lip upon installation, base gasket not in place all around).
    not to say the ignition wasn't faulty though. not the first time a china girl got two problems at once. (communist karma)