Staor Coil Upgrade/ Mod

Discussion in '2-Stroke Engines' started by Timbone, Sep 3, 2015.

  1. Timbone

    Timbone Active Member

    My recent problems with my electrical system were quite a learning experience to me. More than ever, I appreciate the importance of a good stator coil, good spark plug, good CDI, and good wiring.

    One of the great deficiencies of these engines is their lack of electrical to run lighting, which leads to all kinds of issues. I've looked around quite a bit, and I can't find any vendor who sells an upgraded stator coil.

    I lack good electrical system knowledge, but it seems to me that with a more powerful coil, you could send the electric to a box and use transistors, resistors, rectifiers, etc to send the proper level of electricity to the spark plug to fire strong every time AND send the extra to, say, a 9W system for decent, dependable lighting.

    I've examined the old coil and there's not much to it. Couldn't you improve it by simply spinning more copper around it?

    Just thinking out loud...


  2. tzvii

    tzvii New Member

    Yes that will work; wind your own second coil and light away. There are secondary coils sold on eBay for this purpose already that you just bolt in but you could easily make your own.

    I am able to run a lighting system off of my coil (older type with two separate coil windings). The lights aren't really bright enough for me to see from, but they are enough that people can see me in the dark. I made it using two Harbor Freight LED lights, the ones in the blue case that they give away frequently. I epoxied a red brake light cover onto one and stuck it on the back of the bike, and have the other on the front. I have been using this setup for about a year now. I did not bother to rectify the current as I like the flickering from AC.

    You can tell if your coil has the secondary winding if the coil has two separate wires soldered to ground. The coil with just one winding will have only one wire going to the soldered ground connection.
    I have seen these coils sold on eBay from China as "12V" coils. I have not verified the output from it other then knowing it powers the lights I hooked up on it.

    Most of the newer coils I have seen are the type with only one winding; the white wire on these ones is simply soldered in parallel onto the high voltage spark coil (atleast on the ones I have seen). This means that if you try to connect a light to one of the coils with a single winding, the light will take current from your spark and the engine will likely not fire.
  3. crassius

    crassius Well-Known Member

    for a while now, there have been 480ohm coils to replace the 350s that come on most kits - seems the extra power can fry the CDI and my kit supplier has gone back to the 350s

    there is a separate coil that can be fitted into that area to run some lights, or there are setups like screaming roo that have an ignition coil to boost the CDI

    just look around a bit on the net
  4. jaguar

    jaguar Well-Known Member

    the standard stator coil produces plenty of voltage for the CDI to make use of, but the standard CDI doesn't make good use of it which is why it produces a weak spark.