RAW engine, having issues starting. Carb replaced. Possibly no spark? Please help!

Discussion in 'Electrical' started by RawRawRaw, Mar 9, 2013.

  1. RawRawRaw

    RawRawRaw New Member


    I got a project bike with a raw engine on it (I did not install the kit myself, just learning about it through an old used one that was sitting outside for a year)

    Previous owned said he replaced the CDI and spark plug, but did not know much about engines.

    Well, neither do I. But I got it to start a few times.

    I took the carb apart, and the float has a bit of gas in it, and the bowl seal was cracked. So I bought a new carb, nearly identical, and put it on. Same issue.

    It turns as I pedal, but won't kick in.

    The spark plug looks okay, I think:
    https://www.dropbox.com/s/1t8k184g7456zwi/2013-03-09 17.45.39.jpg

    but the part of the (ignition coil?) that connects to the spark plug fell out:
    https://www.dropbox.com/s/27asqoadk5c7zbi/2013-03-09 17.44.55.jpg

    I put it back in, but not sure if the orientation of the copper cylinder piece to the clip looking piece matters, does it?

    I tried taking out the spark plug, connecting it, and pedaling, am I supposed to see a spark?

    I have access to a dmm and such, not sure what to test for, if it is the spark, at this point I have no idea

    I took some pictures of the wiring:

    https://www.dropbox.com/s/9pkzbxfiotkmppr/2013-03-09 19.01.31.jpg

    Two Y-splits:
    https://www.dropbox.com/s/p2okmmia5lg7a1i/2013-03-09 19.01.21.jpg

    Wires from engine:
    https://www.dropbox.com/s/o6o5uffoja0zsr2/2013-03-09 19.13.24.jpg

    White goes to nothing?
    https://www.dropbox.com/s/smuzqbd3n3ygok5/2013-03-09 19.01.14.jpg

    https://www.dropbox.com/s/5nyp2ow7s2u8axc/2013-03-09 19.01.06.jpg

    Green and Yellowred go to kill switch.

    Black from engine goes to yellowred to killswitch, and black to CDI

    blue from engine goes to CDI green and killswitch green

    CDI has black to engine and to killswitchs yellowred and blue to killswitch's green and to engine blue

    white from engine doesn't connect to anything.

    is this wired correctly?

    Any help is greatly appreciated!

  2. Anton

    Anton Administrator Staff Member

    Welcome to the forum! The spark plug cap is a piece of crap. If it fell off where the ignition wire meets it, then it is probably not giving a connection anymore. This is how I fixed mine:

    (Terminal connector soldered onto the ignition wire and then screwed onto the spark plug connector.)

    Yes you should see a spark when you turn the engine over! If there is no spark then this is you problem

    The wiring looks ok. Make sure the white wire is insulated with tape.
  3. RawRawRaw

    RawRawRaw New Member

    Thanks Anton, not sure how to wire liek you did. What is a termincal connector? is that the brass looking thing with a clip in it?

    Is there supposed to be a spring on top of the spark plug?

    My connect just like this:


    The part circled is what fell out and I put back in.

    When I ride it like this there is a spark, but it's between the engine and the wire, not from the spark plug itself. (circled)

    So is it as simple as modifying the connector so the outer tip of the spark plug is touching the wire?

    I insulated the white wire, but before I might've been grounded. Could that of done any damage to the coil/cdi/etc?
  4. Anton

    Anton Administrator Staff Member

    Ok to test for spark you need to make contact between the metal thread of the spark plug and the metal fins of the engine. You want to see a nice spark right at the end of the spark plug as the engine is turning over. Don't touch the end of the spark plug or you will get shock. Hold onto the plastic part of the spark plug cap to avoid this.

    I used a terminal connector for my spark plug connector but I also soldered it.
  5. RawRawRaw

    RawRawRaw New Member

    Got it. Still not sure what a terminal connector, but I got the idea!

    I took off the boot and just stuck the cable on after heatgunning it, threw a ziptie on it and it works!

  6. RawRawRaw

    RawRawRaw New Member

    Temp fix is just sticking the wire directly into the spark plug, lol.

    Not sure how the cable is glued into the CDI or what not, I was thinking just cutting it and splicing a new boot on - objections?
  7. Anton

    Anton Administrator Staff Member

    The ignition wire screws into the top of the spark plug adapter and is supposed to make contact and hold itself on at the same time. You can see the little metal screw bit in this photo. The ignition wire screws onto that.
    Now take that adapter and throw it as far as you can see :annoyed: (but keep the spark plug)

    This is what I used instead. You can unscrew the top of the spark plug (anticlockwise).

    Take the terminal connector, strip back the ignition wire and crimp it on. Then screw it onto the top of the spark plug nice and tight.

    Now of course it will be a little harder to remove your spark plug if you wish to check the color of the spark plug to see how the fuel is burning. But hey at least your bike starts and runs!
  8. RawRawRaw

    RawRawRaw New Member

    Thanks Anton!

    The bike was running fine for 2 days (~6 miles?) and today it just died. Get's spark when I take the plug out so my ghetto fix is working (but i'll probably just get a good boot)

    I had the petcock open all the way from the fuel line, and the previous owner warned me against that claiming 'this engine floods a lot'

    i took off the carb, opened the bowl, a little fuel leaked out, took out the spark plug, hopefully it will evaporate overnight, if it's flooded.

    any advice regarding this issue?
  9. Anton

    Anton Administrator Staff Member

    The first thing I would say is that you should definitely upgrade your ghetto fix of inserting the ignition wire into the top of the spark plug. That will cause all sorts of reliability issues. If the wire vibrates it will not make contact and the bike will not run.
  10. wan37

    wan37 Member