Chinese 2 stroke- Wiring How To's (basic and advanced)

Discussion in 'Electrical' started by gone_fishin, Jun 21, 2007.

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  1. gone_fishin

    gone_fishin Guest

    blue/green to blue/green (pos)

    black to black (neg)

    white capped off, or used for single 6V/3W bulb (pos)

    insulate the connections from ground & each other

    splice killswitch into blue/green connection EDIT:see link in post #5
    (with a 2-wire switch, one wire into blue/green splice, other side to ground/frame)

    kindly post this link in reply to any questions about basic wiring.

  2. fastboy9

    fastboy9 Member

    You want one wire jammed into your blue to blue connection, and the other clamped on to the frame to act as a ground. If your engine starts to run badly straight after then the kill switch is dodgy. Then in that case I would recommend installing a switch on the blue wire, no problems there!

  3. fastboy9

    fastboy9 Member

    The thing that lets a lot of builds down is the dodgy job of wiring everything. If you want your bike to look professional then doing a few things can make your job look clean, and will also make it more reliable as you wont have wires all over the place loosely held together.

    So to take power for a light bulb from the engine or not to is the question?

    The answer is not to ! Why? Because by taking power from the engine
    You are actually starving the engine of electricity needed to generate a spark.
    It's as simple as that. Better to use an external power source for lights
    like a rechargeable battery.

    Moving on to good wiring practice. There are no definitive was to do it
    but I thought id share some of my ideas with you.

    6mm Heat shrink comes in many different colours and can be purchased off ebay
    for next to nothing. You can give your wiring a neat finish by following the
    steps below.

    Before we get started you may want to take the white wire, fold it in half and insert
    it into the sleeve. The white wire is used to add a 6v light bulb that is powered from the engine and it is not recomended that you use it, it is just much better to buy yourself an externally powered one.

    Take one of the heat shrinks and cut it in half these will be used to cover the two connections of the CDI unit. The longer piece will be used to cover the base of the wiring coming from the engine for a nice and clean finish.

    Connect the black wire of the kill switch into the blue or green wire of the engine, you can use some solder here if you like.

    Connect the blue/green wire from the engine to the blue/green wire of the CDI unit and then connect the black wire of the engine to the black wire of the CDI unit. Now fix the red wire of the kill switch onto the frame by using the top bottle holder screw and the wiring is complete.

    Also while your at it, why not cable tie your wires to the frame. Another good thing to do is seal the sleeve coming out from the bottom of the engine, I used epoxy resin on mine, but a good dollop of vaseline would do the job.

    It would be a good idea to put the CDI inside some sort of small plastic bag to protect it from water too.

    The pictures show how the kill switch should be wired up. Alternatively you could make yourself a much more efficient kill switch by putting a switch on the blue wire; this thread here goes into a lot of detail in to making one. It puts less strain on your magneto therefore making your parts more reliable.

    Any body else have any good ideas to add to this?


    Attached Files:

    Last edited: Jul 8, 2008
  4. screaming emu

    screaming emu Member


    Yeah I'd like to add that doing away with the electrical connectors that come stock with HT motors and changing them to spade connectors (from local auto shop) fit much tighter and are less likely to come undone. I've always wired black to black, blue to blue, white to one of the throttle wires and the other throttle wire to the drink bottle holder bolt to earth it. I have never had any electrical problems and have built and sold many bikes like this. This way saves piggy backing any wires.
  5. nickk

    nickk New Member

    wiring how to's

    hi all
    adam the paper works tells you that thats 7 volt output and that way that you got it would cause the engine to cut out or missfire
    but you say that it works ok , very strange i solder all connections cut off the connectors (water can get in) and heat shrink the joins
    what ever works hey
    ta nickk
    Last edited: Jan 6, 2009
  6. This is the way my instructions said to wire the kill switch, and with over a 1000 miles I have had no problems.........
  7. buzbikebklyn1

    buzbikebklyn1 New Member

    Black, Blue And White...

    Whats the white wire for?
  8. Bryan Smith

    Bryan Smith Member

    Mine is wired (from engine):
    Black to black wire and grounded to frame. Blue to blue wire. White runs to kill switch and to 6v 4 amp headlamp. Other wire from kill switch to frame (ground) and also other side of headlamp to frame.

    If you want more pep, leave out the headlamp or use low power LED's.
    Best option is to use external power source for lights.

    I used wire the kill switch to the high voltage blue wire, but it kept shocking me from time to time. The kill switch to white wire works very well.


    What about charging

    For instance, I have a brand new battery, wich i got from the Interstate battery guy that restocks our shop. I asked him to get me a battery for my bike. A 6 volt, small amp battery, that could be possible to use on my bike for reserve power or some other electrical use. But what about charging, could i over charge it, or do i need to build a small regulator. Mabay it wont even work at all. The Interstate battery guy gave me a 6 volt, 7 ah, sealed, A.G.M. (absorbed glass mat) battery. Looks like a tall, thin, pocket bike battery. Its like5 x 7 x 1 1/2. He gave it to me but said it would be like 20 bucks. Does any one have any info that they could shed. I havent even put the multi meter on my bike to see what the charastics of the voltage and amperage were at different r.p.m.s.
  10. GearNut

    GearNut Active Member

    You will need a single diode rectifier/ regulator to produce clean enough current and prevent overcharging the battery. The white wire is good for 6 to 7 volts, 3 watts. calculated at 6.5 volts, that's .461 amps. A battery likes to be charged at 1/10 it's rated amperage.
    for your battery that is 0.7 amps. It will take a long time before the battery gets overcharged, but safe is better that sorry.
  11. NBP MotorSports

    NBP MotorSports New Member

    So...Why couldn't you take the key assembly from a pocket rocket and use that as the kill(on/off)switch?
  12. DuctTapedGoat

    DuctTapedGoat Active Member

    You could easily replace the kill switch with a keyed switch.

    That doesn't change the fact that more often than not, when the white wire is in the circuit, your kill switch fails - regardless of if it was on a keyed switch or a push button kill switch.
  13. juliman

    juliman Member

    i made a neat little keyed switch from some clear acrylic, a pocket rocket switch i had lying around, a rubber dust cover from a bearing cuz the nut for the switch shattered, which i press fit onto the switch to hold it on, and soldered it all together and it looks awesome , i might try to get some pics
  14. Ryno

    Ryno Member

    My kill switch is wired like everyone says, but it STILL won't work. Instead of a black and white wire coming from my switch, I have a red/yellow wire and a green wire. My bike is wired like this

    Blue engine - Blue CDI
    Black Engine - Black CDI

    Red/Yellow Killswitch - Blue CDI
    Green Killswitch - Grounded to frame

    What could possibly be wrong here?
  15. DuctTapedGoat

    DuctTapedGoat Active Member

    Take your green from kill switch and hook it up to the black on the engine/cdi.
  16. Ryno

    Ryno Member

    But the green wire has a metal loop on it, isn't that supposed to be grounded to the frame?
  17. DuctTapedGoat

    DuctTapedGoat Active Member

    It's not necessary at all.

    That is how the kit instructions tell you do, and you "can", but it's a more secure connection to ground it via the black wire.

    As well, this means you don't have to strip paint from your bike. Give it a shot, you'll see.

    Lastly - where is your white wire? If it's not capped off, cap it off.
  18. Ryno

    Ryno Member

    Thanks for the instruction, I'll let you know how it goes when I get the chance
  19. blue

    blue New Member

    on my chines 2 stroke 70cc engine there is not a green wire
  20. DuctTapedGoat

    DuctTapedGoat Active Member

    The kill switch wires can be switched, all they do is complete a circuit.

    :::::WIRING GUIDE :::::

    Okay, first we will take note of our wires.

    NOTE: Different brands tend to use different colors for some wires, so use the process of elimination to determine what color a wire is if it is not stated here.

    *Kill Switch Wires : Green Wire & Red/Yellow Wire.
    *Engine Wires : Blue Wire & Black Wire & White Wire.
    *CDI Wires: Blue Wire & Black Wire.
    *Other Stuff: Wire Cap

    Now that you know what wires you have, it's time to connect them.

    1. Engine's Blue Wire to CDI's Blue Wire.
    2. Engine's Black Wire to CDI's Black Wire.
    3. Kill Switch's Green Wire to Engine's & CDI's Black Wire.
    4. Kill Switch's Red/Yellow Wire to Engine's & CDI's Blue Wire.
    5. Engine's White Wire to Wire Cap.