getting the kill switch to work

Discussion in '2-Stroke Engines' started by dadesign, Aug 5, 2010.

  1. dadesign

    dadesign New Member

    this is the last step. I have had the bike running good for the last few weeks now but the kill switch is still not attached. I have been killing with the choke.

    This would be fine but after getting it running and broken in I have decided to sell it already.

    so I was hoping someone could tell me the proper way to hook this up again to get it to work properly, the white wire is questionable. the vendor told me it should be in the circut and others have said cap it off.

    i have also read it dont matter which of the two wires go to the blue or black from the enging and CDI module.

    so if i could get some clarity on that. I want it to work so it will be a completed project and ready to sell as done.

    The reason is I have decided that it was to be personal transportation(not having a car) but had a near miss accident with someone not paying attention and almost ended up under their back wheels had it not been for quick acceleration and reflexes. still it really scared me and made me realize, while fun, this will not work for me.

    this project is not in vain though. i learned alot about small engines from it. knowledge i needed. my next vehicle will be a Chinese scooter and i know they need work like that too. this knowledge will be a stepping stone towards it.

    so thanks for all the assistance and knowledge on it. I will be able to assist others in the area now

  2. AussieSteve

    AussieSteve Active Member

    Others will advise differently, but I reckon you should connect the kill switch between the white wire and engine ground. That's what the white wire is there for. There is absolutely no reason to cap it off.

    My 2c worth.
  3. motorpsycho

    motorpsycho Active Member

    here's how mine is hooked up on both of my bikes.
    black wire from engine, black wire from cdi box and black wire from the kill switch all hooked together.
    blue wire from engine, blue wire from cdi box and yellow wire from kill switch all hooked together.
    the white wire is not hooked to anything, but make sure the end is cut off clean with no bare wires showing, and cover it with heat shrink or electrical tape at the least.
    this is exactly how the wiring diagram is in my instruction book. the white wire is there to hook up a low voltage headlight. but we all know that there is not enough power from the mag. at the white wire to power a 6 volt headlight AND provide strong spark to the spark plug. hook up a headlight to the white wire, and you will lose voltage from the mag., resulting in too weak of a spark to make the engine run.

    if you haven't already, cut off the snap together wire connectors and solder all wire connections, and cover them with heat shrink or black tape (at the least)
    those connectors are junk, and crimp on butt connectors or any other crimp on connectors are not very reliable either.
    if you're going to do the wiring right, twist the bare wires together and solder them for strong, dependable connections.
    Last edited: Aug 5, 2010
  4. pbeggs

    pbeggs Member

    white wire is for kill switch,.. can also be tapped for 6 volt light,.. put a on/off switch in for ease of starting (once warmed up i dont have any trouble starting with the light on,.. just need to turn it of for the first start up of the day.)

    otherwise black to black
    blue to blue

    one kill switch wire to white the other to ground (engine block or black wire)
  5. motorpsycho

    motorpsycho Active Member

    my kill switch has been hooked up the way i described for over a year now and it works great. I just finished my second build and wired it the same way. i have nothing hooked to the white wire on either one of my bikes.
    so there must be more than one way to hook up the kill switch, i guess it;s a matter of preferance.
    I had a headlight hooked up to the white wire on one of my bikes, and even after the engine was warm, turning on the headlight instantly killed the engine.
    this was when the engine was only about a week old, and i was using a 3 watt lightbulb in the headlight.
  6. GearNut

    GearNut Active Member

    3 watts is the maximum rated output for the white wire. With the poor quality control of these engines, alot of the mags out there will not even supply that small amount of power. The result is no signal going to the CDI box.
  7. dadesign

    dadesign New Member

    i was told before to do this and did but wouldnt turn over so i thought the kill switch was bad, took it out of the circut, and they are tied up.

    the colors stated dont match. mine are yellow and red and the other wire is green and blue

    i think i red that it didnt matter which color wire went to the blue and blacks from the engine and cdi. anyone confirm that.

    today i am taking off the handlegrips to fill the handlebars with spray foam to cut down on vibrations and i would like to get this done as well
  8. pbeggs

    pbeggs Member

    you should have 3 wires coming from the engine
    white, black and blue

    you should have 2 wires from the cdi blue and black

    you should have 2 wires coming from the kill switch (colors dont matter)

    i would hook blue from engine to blue from cdi
    black from engine to black from cdi

    white from engine to yellow/red kill switch
    green/blue from kill switch to either black from engine,.. or hook directly to engine block (motor mount stud,.. ect)

    ive wired a few this way
  9. Bryan Smith

    Bryan Smith Member

    I wired the black wire from the engine to the CDI and also the frame of the bike as a ground. My kill switch is wired between the white wire and bike frame(black wire). This setup works great.

    I used to have a keyed kill switch between the black and the blue wire, but it would shock the pee out of me if I happened to be grounded at the time I turned it off. Didn't take long to decide to change it to the way I have it now.
  10. lilmilo

    lilmilo New Member

    wire a toggle switch inline on blue wire between cdi and motor. been running like that for about 4 months with no issues. apparently from research I've done grounding method can affect cdi or magneto.
  11. Bryan Smith

    Bryan Smith Member

    From two years of reading posts and tinkering with these bikes. I'm pretty much convinced that "grounding the white wire causes cdi or magneto problems" is a wives tail perpetuated by rumor. Briggs and Stratton has been using this method with their kill switches a lot longer than I've been around. An inline switch in the blue wire will work just as well (I used to do it that way), but you always run the risk if getting a jolt intended for the spark plug and It's probably arcing across the contacts a little as you flip the switch which may eventually erode the contacts...but this is probably not that big a deal as switches are relatively cheap.