Working on CDI

Discussion in 'Electrical' started by Andy h, Aug 5, 2011.

  1. Andy h

    Andy h New Member

    There are alot of first time / what to do when you get a HT motor threads that recommend replacing spark wire/head with something better from a auto store. I am not one to steer clear from good advice so lets look at why. Personally I didnt know. This is from my 66cc.

    As you can see the fitting in the cap was cracked. I poked it with a screw driver and it fell apart and fell onto the work bench. It screws into the top and can be removed via screwdriver.

    The cap was lose. I gave it a few twists and it came off. The cap is a screw that when screwed into the "wire" makes contact with about 5 thin copper wires running through the rubber.

    I can clearly see why you would want to replace this. I didn't take it apart as it kinda fell apart while looking at it.

    So now to replace the wire. I read here that the wire unscrews from the CDI. After torquing on it I am having my doubts. Maybe its not screwed? I couldnt tell with the "shield" that was where the wire met the CDI so I removed it.

    Does not appear to have threads meeting the CDI. Just the sealant and the wire going into it. I saw a picture posted earlier showing it unscrews but of course I cannot find it now.

    Are all CDI units not the same? It wouldn't surprise me. Or are the threads abit deeper under the sealant? Any help would be appreciated.

    Oh and I forgot to add... If I cannot replace the wire the thing is falling apart. Is there a alternative CDI that is a little better put together?
    Last edited: Aug 5, 2011

  2. Al.Fisherman

    Al.Fisherman Active Member

    Yours looks like there is no screw. Take a new wire and cap, strip back about 1/2" insulation, peel wire back over the insulation, stick it into and glue it in. Umm seems like this is one of the times JB Weld would work, actually any epoxy will do the same. If I had to glue one into the CDI, I'd use product that they sell about the size of a ketsup package, made for electrical contacts. I see them all the time at the counter, both at Auto Zone, Advance, and O'Rileys. Forget the name at the moment. Here it is...Dieletric Grease...just a very small amount where the wire meets the CDI electrode.
    Last edited: Aug 5, 2011
  3. Andy h

    Andy h New Member

    Thanks for the reply. I plan to do it exactly as you explained. To be safe I'm going to place some calls and see if I can't get another CDI on the way that has a cable screwed in. I may make a mistake or at least its a spare.

    I'm on 12hr weekend midnights and I don't do to much tinkering after work. I'll post some pictures of how its going next week when I'm off. I want to go deeper into the epoxy filler and see what's there.