Engine Trouble 80cc won't start

Discussion in '2-Stroke Engines' started by Alexander Moschella, Sep 7, 2012.

  1. Alexander Moschella

    Alexander Moschella New Member

    I have an 80cc bike kit that I have had going twice, but the after the second time nothing happens anymore. I have tried the following troubleshooting procedures.
    1 have soldered the connections between the CDI box and the magneto
    2 I have used a high-quality synthetic two-stroke oil with a 16 to 1 ratio in the engine
    3 between the red and the black wire from the magneto there is a resistance of .3 K ohms, which is in the normal range
    4 the voltage coming from the CDI box climbs and then drops when hooked up from the blue and red wire into a voltmeter
    5 the cylinder is making compression noises when I take the spark plug out
    6 I am getting a spark but I'm not sure if it is timed correctly or strong enough
    7 the kill switch is not connected, because I've found that it is defective

    Can anyone help me with further troubleshooting? It would be much appreciated.
    thanks a lot,

  2. crassius

    crassius Well-Known Member

    not sure about your stator coil - I have seen older coils with a brownish wire where there is normally a blue wire and a blue wire where we now have a white wire

    I have not seen a red wire on any of them so far, so I can't do much for you except to say that if you have spark, you're probably hooked up right. I'd check that the engine is really turning when the spark plug is in and try a different plug in case it won't spark under compression.
  3. Alexander Moschella

    Alexander Moschella New Member

    Sorry I got the colors all wrong. (FYI the wires are connected backwards in the picture because I was trying a suggestion from the vendor.)

    In line with what you said, my latest theory after a couple hours on the forum is that either the head bolts are loose and I am losing compression, or my spark plug is bad.
    Help is greatly appreciated :grin5:
    IMG_0517 (1280x960).jpg IMG_0516.jpg
  4. motorpsycho

    motorpsycho Active Member

    are you absolutly sure that fuel is getting into the float bowl of the carb?
    if your float is stuck in the up position, you'll have a dry float bowl, a dry float bowl means no fuel for the engine to run on.
    try giving it a shot of starting fluid and see if it fires.
    if it does, you have a fuel delivery problem.
    I see that you have fuel in your fuel line, but that doesn't mean that the fuel is actually going into the float bowl.

    you should also install an in line fuel filter because it;'s also possible that debris from inside the gas tank has gotten into the carb, clogging the main jet.
    this will also make the engine not run because it can't get any fuel.
    16:1 is too rich in my opinion, even for break in.
    20:1 is better for break in because at 16:1, there's just too much oil in the gas for it to run right.
  5. Alexander Moschella

    Alexander Moschella New Member

    Thanks for the reply,
    1) how to do I fix the float and the jet if they are clogged?
    2) Which in line filter should i buy?
    3) I will dilute the mixture a bit
    Thanks for the help!!! this bike will be a great way to get around town
  6. Alexander Moschella

    Alexander Moschella New Member

    I got my HT going yesterday...all that was wrong was the clutch was tuned incorrectly.
    Any suggestions on part upgrades for the future or general tips that I wouldn't know.
    Thanks for all the help!!!!!!!