Need advice from people with experience

Discussion in '2-Stroke Engines' started by tankaray, May 3, 2009.

  1. tankaray

    tankaray New Member

    I am tuning my bike up heavy duty redoing gaskets and what not. I went to try and start my bike and it wouldnt start. I bought a new spark plug and did a spark test Im getting nothing. Is it most likley the CDI or the magneto? I am guessing the CDI just because that seems more common. How do you determine which to replace? or is replacing both at once best? Also where would I find a CDI that is desighned for my bike? it is an 80cc 2 stroke motor. I cant wait to get this thing running again. please help

  2. duivendyk

    duivendyk Guest

    Can you get a hold of a voltohm meter?If so you can do some tests to find out what gives ( CDI or power coil in engine).Let me know and I will give you instructions.
  3. tankaray

    tankaray New Member

    I can borrow one from work. do I need to test each of them seperatley?
  4. crazeehorse

    crazeehorse Member

    have you tried it with the kill switch unhooked from the circuit? if not try that first. i have one go bad, it grounds the circuit, & prevents it from geting fire to stop your engine. if it gets stuck, and many do it will cause a no fire condition.
  5. Pablo

    Pablo Motored Bikes Sponsor

    It's actually most common that the PLUG wire is bad. Are you using the stock plug wire?

    Do the easy stuff first before you buy stuff.

    So it was running at some point. Then you changed X and it wouldn't start at that point.(?) What did you change? (X=???)
    Last edited: May 3, 2009
  6. tankaray

    tankaray New Member

    As far as the motor goes the only thing I have (besides a few cheap gaskets) changed is the spark plug in an attempt to see if that would fix the problem. if its the plug wire chances are I would need a new CDI because the cord goes into the housing of the CDI and there is no way to open mine up. If there is some cheap easy way to fix this fill me in please and Ive tried disconnecting the kill switch and that made no difference Im still not getting a spark
    Last edited: May 3, 2009
  7. spad4me

    spad4me Member

    The spark plug wire SCREWS into a screw that is centered in the cdi where the spark plug wire exits the cdi.

    It does unscrew.
    A decent replacement is hard to find.
    Pablo sells a nice one.
    Did you gap your sparkplug.
    Carefully unscrew it and check the gap should be 20 to 25 thousands.
    You need fuel air and spark to run.
    Check your gaskets for leaks.
    Remove the sparkplug.
    Place a couple of drops of gas in the cylinder.
    Replace the plug .
    Try to start it .
  8. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    Test them with an ohm ya have one? :grin5:
    There are many posts here with what the measurements are.

    Actually I have found more magneto's bad than CDI's

    A decent replacement is NOT hard to find.
    Look in the trash outside an automotive parts store.

    Any quality silicon automotive spark plug lead can be used on your bike
    Cut the lead to length and screw it into the CDI.
    Last edited: May 4, 2009